What is the European Union (EU)?
The European Union (EU) is a unique supranational organization – essentially a political and economic union of currently 27 European countries. It emerged after World War II with the goal of integrating European economies to secure peace and prosperity. The modern EU was formally established by the 1992 Maastricht Treaty, building on earlier communities dating back to the 1950s. Member states agree to pool parts of their sovereignty and delegate certain powers to common EU institutions.
Institutions: The EU’s governance structure includes seven main institutions. Key bodies are the European Commission (the executive branch proposing and enforcing laws), the Council of the European Union (representing member state governments), and the European Parliament (a directly elected legislature). There is also the European Council (heads of state or government, setting broad direction), the Court of Justice of the EU (ensuring uniform interpretation of EU law), the European Central Bank (managing the euro currency for participating states), and the European Court of Auditors. Through these institutions, the EU can make laws, manage a common budget, and coordinate policies in areas like trade, agriculture, environment, and regional development. Decisions often require a balance of supranational and intergovernmental agreement, reflecting the EU’s blend of shared sovereignty and national interests.
Goals and Values: The EU’s foundational aims include promoting peace and the well-being of its peoples, ensuring freedom of movement and justice within its borders, and creating a single internal market for goods, services, capital, and labor. The EU also strives for sustainable development with balanced economic growth, price stability, full employment, and social progress, alongside a high level of environmental protection. It seeks to uphold common values such as human dignity, democracy, equality, rule of law, and human rights across member countries. In the wider world, the EU aims to promote its values and contribute to global peace, security, free and fair trade, poverty eradication, and human rights protection, acting in strict observance of international law. These goals are enshrined in EU treaties and underscore the Union’s identity as not just an economic bloc but also a community of values and law.
In summary, the EU is a treaty-based union of European states working collectively through common institutions to achieve economic integration and political cooperation. It has a single market and (for 20 countries) a shared currency (the euro), enforces common policies in many domains, and projects influence as one of the world’s largest economic entities. Importantly, it was designed to bind countries together so closely – economically and politically – that violent conflict among them would be unthinkable. This guiding philosophy earned the EU the Nobel Peace Prize in 2012 for advancing peace and reconciliation in Europe.
What is the United Kingdom (UK)?
The United Kingdom (UK) is a sovereign nation-state in northwestern Europe, consisting of four constituent countries: England, Scotland, Wales, and Northern Ireland. It is a constitutional monarchy with a parliamentary democracy. This means it has a ceremonial head of state (currently King Charles III) while political power is exercised by an elected Parliament and the Prime Minister. Executive authority resides in the Prime Minister and Cabinet, who must command a majority in the House of Commons (the primary legislative chamber), and there is also an independent judiciary upholding the rule of law. The UK’s system is unitary but with devolved administrations in Scotland, Wales, and Northern Ireland, each of which has some self-governing powers.
National Identity: Culturally and historically, the UK possesses a strong sense of national identity that has at times been ambivalent toward European integration. It was a global imperial power in the 19th–20th centuries and still maintains ties to many former colonies through the Commonwealth of Nations. English is a global lingua franca largely due to British historical influence. The UK often views itself as a distinct global actor – famously, wartime Prime Minister Winston Churchill described Britain’s stance on Europe as being “with Europe, but not of it… linked, but not comprised”. This quote encapsulated a strain of British thought: cooperative with European neighbors, yet retaining a degree of separation and sovereignty. Indeed, throughout its EU membership, the UK secured several opt-outs (for example, it kept its own currency and controls on its borders) which reflected this cautious approach to deeper integration.
International Role: The UK has a prominent international profile. It is one of only five permanent members of the United Nations Security Council and a founding member of the North Atlantic Treaty Organization (NATO). It ranks among the world’s largest economies (a member of the G7 and G20) and is a recognized nuclear power. British diplomacy often emphasizes the “special relationship” with the United States – a close alignment on defense, intelligence, and trade – as well as global free trade and a network of alliances beyond Europe. In recent years, British leaders have promoted a vision of “Global Britain,” suggesting the UK can play an agile global role in trade and foreign policy, independently of the EU. This has included pursuing trade agreements across the world and initiatives like the AUKUS security pact with the US and Australia. The UK’s soft power is significant too, bolstered by the English language, British media and education, and cultural industries (from literature to music) that have worldwide reach. All these factors contribute to the UK’s self-image as an important, if medium-sized, power with global connections and responsibilities.
In essence, the UK is a democratic, historically influential country with a strong national identity and global ties. It values its sovereign decision-making but also has to balance that with the realities of interdependence in trade and security. These characteristics have framed how the UK interacted with the European Union and inform the current debate about whether it should rejoin the EU after having left.
Historical Background: The UK’s EU Membership, Brexit, and Aftermath (pre-2025)
The UK’s relationship with the European Union has evolved over decades and is crucial context for the rejoining debate. The UK joined the European Economic Community (EEC) – the EU’s predecessor – in 1973, after initial hesitation and a veto of its entry by France in the 1960s. Membership was confirmed by a British referendum in 1975. Over the next several decades, the UK was often described as an “awkward partner” in the EU, benefiting from access to the single market but frequently skeptical of further political integration. The UK obtained special terms in the EU, including a rebate on its budget contributions and opt-outs from certain policies. Notably, the UK never adopted the euro, keeping the British Pound, and it stayed outside the Schengen Area (which allows passport-free travel across many European countries). These exceptions underscored the UK’s partial detachment even while it was an EU member.
Brexit Referendum: Long-simmering Euroscepticism came to a head in June 2016, when the UK held a nationwide referendum on whether to remain in or leave the EU. This followed years of domestic debate over issues like EU regulations, immigration, and sovereignty. In a result that surprised many, 52% of voters chose to “Leave” the EU, versus 48% “Remain.” This narrow victory for the Leave campaign – a phenomenon quickly dubbed “Brexit” (British exit) – revealed a country divided over the EU. Political scientists note various drivers behind the vote: concerns about high immigration (especially from EU free movement), economic grievances and deindustrialization in some regions, and a desire to “take back control” of laws and borders were prominent themes. The outcome prompted the resignation of then-Prime Minister David Cameron and set the UK on an unprecedented course to withdraw from the Union after over 40 years of membership.
Negotiation and Withdrawal: Implementing Brexit proved complex. EU law was deeply woven into the UK’s legal and economic system, so unraveling those ties required extensive negotiation. The UK formally notified the EU of its intent to leave in March 2017, triggering a two-year negotiating period under Article 50 of the EU Treaty. Political turmoil ensued: the UK went through two general elections (2017 and 2019) and three Prime Ministers during the Brexit process. After protracted talks and several deadline extensions, the UK government led by Boris Johnson struck a Withdrawal Agreement with the EU in late 2019, including a “divorce bill” settlement and provisions to protect the Ireland/Northern Ireland border. On 31 January 2020 at 11 pm London time, the UK officially left the EU, ending its membership of nearly 47 years. This date marked the start of a transition period, during which EU rules still applied while a future UK-EU trade deal was hashed out.
At the end of 2020, the two sides concluded a Trade and Cooperation Agreement (TCA) defining their new relationship. The UK chose to leave both the EU single market and customs union, meaning that from January 2021 onward, new trade barriers arose between Britain and the continent. Tariffs and quotas were generally avoided under the deal, but customs checks, regulatory inspections, and other “red tape” were introduced for the first time in decades for UK-EU commerce. One particularly thorny issue was Northern Ireland: to keep an open land border on the island of Ireland (in line with the Good Friday peace agreement), Northern Ireland effectively remained aligned with many EU single market rules. This created an internal UK trade border in the Irish Sea, a point of ongoing political friction. The Windsor Framework of 2023 refined these Northern Ireland arrangements to ease intra-UK trade, but unionists in Northern Ireland and some Brexiteers still worry about EU law applying on UK soil.
Post-Brexit Aftermath (2020–2025): Brexit’s impact has been significant, though often difficult to isolate due to concurrent events like the COVID-19 pandemic and Russia’s war in Ukraine. Nonetheless, by 2025 several trends were evident:
- Economic Effects: Leaving the EU introduced new friction in trade. UK exports to the EU fell sharply in early 2021 and have not fully recovered in some sectors. Businesses face higher costs and bureaucracy when trading with Europe – for example, British exporters have had to navigate rules-of-origin forms, veterinary inspections on food products, and other non-tariff barriers. Some firms, especially smaller ones, stopped exporting to the EU or relocated parts of their operations to an EU member state to avoid barriers. The UK’s independent fiscal watchdog, the Office for Budget Responsibility (OBR), estimated that as a result of Brexit, the UK’s total imports and exports will be around 15% lower in the long run than they would have been inside the EU, and productivity will be about 4% lower. This implies a significant long-term economic cost. By 2023, the UK was the only G7 economy that had not regained its pre–pandemic GDP level – a situation various analysts partly attribute to Brexit’s drag on trade and investment (though other factors are also at play). On the other hand, Brexit supporters highlight that the UK has gained the freedom to strike its own trade deals. The UK has signed or rolled over trade agreements with countries like Japan, Canada, Australia, and New Zealand, and in 2024 it joined the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), a trade pact spanning Asia and the Americas. However, experts note these deals so far have a very modest economic impact compared to trade lost with the EU – for instance, the CPTPP is estimated to boost UK GDP by only ~0.1% in the long run. Overall, by 2025 the UK economy has grown more slowly than it likely would have inside the EU’s single market, according to most economists.
- Social and Mobility Effects: One immediate change was the end of free movement of people between the UK and EU. EU nationals now face visa requirements to live and work in Britain, and UK citizens lost automatic rights to live, work, or retire in EU countries. This has had consequences in the UK labor market (sectors from agriculture to healthcare felt worker shortages when EU migration fell) and for individuals (for example, British retirees in Spain or British students who once easily joined the EU’s Erasmus exchange program). Paradoxically, overall immigration to the UK reached record highs post-Brexit, because while EU migration dropped, the UK opened new visa routes for non-European migrants, and many more international students and workers came from outside the EU. Brexit was in part driven by a desire to control immigration, but by 2025 the UK finds itself with higher net migration than when it was in the EU, only now with more migrants coming from Asia and Africa instead of Europe. Culturally, Brexit also exposed or exacerbated social divides – between younger, urban, pro-EU segments of the population and older or more rural Eurosceptic segments, as well as between England and Scotland (the latter voted strongly to remain in the EU).
- Political Effects: Brexit reordered British politics. It led to the fall of two Prime Ministers (Cameron and Theresa May) and the rise of Boris Johnson, who campaigned as the leader to “Get Brexit Done.” Once Brexit was formally achieved, political debate shifted to how to manage the new relationship with Europe. By 2024, the Conservative government that led Brexit had lost popularity amid economic difficulties, and the opposition Labour Party (under Keir Starmer) won the 2024 general election. Starmer’s government has taken a pragmatically pro-European turn in tone, seeking to “reset” UK–EU relations. However, Labour has explicitly ruled out any attempt to rejoin the EU (or even its single market or customs union) in the short-to-medium term, largely to respect the 2016 vote and avoid reopening old wounds. Instead, the focus has been on incremental improvements: for example, the UK has negotiated closer cooperation on issues like security and re-entered the EU’s Horizon Europe scientific research program (as an associate member) in 2023. Despite these moves, Brexit remains a contentious topic domestically. Notably, Scotland – where a strong majority voted Remain in 2016 – has seen its pro-independence leaders argue that an independent Scotland could rejoin the EU, a prospect that has some support across Europe. Brexit thus fueled Scotland’s drive for another independence referendum, though as of 2025 the UK government continues to oppose such a vote.
- Public Opinion: Attitudes in Britain have shifted since 2016. By the five-year anniversary of Brexit in 2021, opinion polls showed a growing number of Britons regret the decision. That trend solidified – by 2025, a consistent majority of respondents say that Brexit was a “mistake” in hindsight. Polling in late 2024 indicated that about 57% of Britons would vote to rejoin the EU if another referendum were held, according to some surveys (though results vary by poll). Importantly, however, “rejoin” has not yet been a front-line political campaign pledge by any potential governing party, and many people are wary of revisiting the polarizing fight so soon. The concept of rejoining the EU remains “distant” for now, as the scars of the Brexit battles are still healing. Even some pro-European analysts suggest that the UK would need a sustained period of consensus and perhaps a new generation of voters before attempting to re-enter the Union. On the EU side, leaders have generally taken a “door is open” stance – they did not want Brexit to happen, and influential figures like European Commission President Ursula von der Leyen have hinted that they believe the UK could one day find its way back to the EU. At the same time, there is recognition in Europe that any UK return should be on different terms: it would likely require strong British public support and might come without the special perks the UK formerly enjoyed (no new rebate or opt-outs).
This historical context sets the stage for the debate on the resolution: “The United Kingdom should rejoin the European Union.” Below, we present the major arguments on both sides of this question, as of 2025, considering economic, political, social, legal, and geostrategic dimensions. The perspectives of stakeholders within the UK, in the EU, and internationally will be noted, drawing on the developments of both the pre-Brexit and post-Brexit periods.
Arguments in Favor of the UK Rejoining the EU
Advocates for the UK rejoining the European Union (“Rejoiners”) argue that Brexit has been detrimental in numerous ways, and that renewed EU membership would yield significant benefits. Their case spans economic gains, political influence, social opportunities, diplomatic and security advantages, legal alignment, and broader strategic considerations. Proponents draw on evidence from the Brexit experience – pointing to losses incurred since 2020 – as well as the advantages the UK used to enjoy as an EU member. Below are the major pro-rejoin arguments in 2025:
Economic Benefits and Market Access
Supporters of rejoining first and foremost highlight the economic advantages of EU membership. The EU is the world’s second-largest economy and the UK’s nearest and biggest trading partner. Rejoining would restore full access to the EU single market, eliminating the trade barriers, extra costs, and paperwork that appeared after Brexit. British exporters would again be able to sell to 27 other European countries seamlessly, and supply chains could operate without customs frictions. This is projected to boost UK growth, as the EU market accounts for roughly 45% of UK exports and a similar share of imports. In 2020, leaving the EU’s single market introduced frictions that are forecast to reduce Britain’s trade by about -15% in the long run compared to staying in the EU. Pro-rejoin economists argue that regaining membership could undo many of these losses. The UK would also likely see higher foreign investment – historically, many international firms (in sectors like automotive and finance) invested in Britain because it was a gateway to Europe. Since Brexit, some of that investment has shifted to EU member states. Rejoining the EU could make the UK a more attractive investment hub again.
Evidence from the post-Brexit period is often cited: the Office for Budget Responsibility and other analysts have concluded Brexit has been a drag on the UK economy, contributing to slower growth and reduced competitiveness. By 2025, UK GDP is still below its 2019 level (unique among G7 countries), and trade-intensive industries have been hit hard by new EU frictions. Proponents say returning to the EU would remove these frictions, helping businesses large and small. Small firms, in particular, which struggled with new export rules, would find it far easier to revive business on the continent. Even larger companies, like car manufacturers, which face complex “rules of origin” tariffs under the current UK-EU deal, would benefit from the UK being back inside the common regulatory and tariff regime of the EU.
Furthermore, EU membership brings economic stability and resources. The EU budget directs funds to poorer regions and for infrastructure, research, and development. The UK, as a member, received significant EU funding for science (through programs like Horizon Europe), for farmers (via the Common Agricultural Policy), and for regional development in places like Wales and Cornwall. After Brexit, the UK government attempted to replace some of these programs domestically, but many regions and researchers have expressed that funding gaps remain. Rejoining would reopen access to these EU funds and collaborative projects. For example, British universities and scientists would automatically be part of EU research networks and grants, beyond the limited association the UK negotiated in 2023. British students would likely regain access to the Erasmus+ exchange program, which the UK withdrew from post-Brexit, thus restoring opportunities to study across Europe.
In sum, the economic argument is that Brexit has made the UK poorer than it otherwise would be, whereas EU membership would “boost the UK economy,” in the words of a 2025 public petition for rejoining. Advocates contend that any membership fees the UK would pay are trivial compared to the economic growth from single market participation – a cost-benefit calculation evidenced by the fact that no other advanced economy has chosen to leave the EU once in. On the contrary, several countries in eastern Europe have seen their economies transformed positively by joining the EU’s integrated market. Rejoiners believe the UK could similarly revitalize its economy by reversing Brexit, citing estimates that doing so could over time add percentage points back onto GDP growth (essentially recouping the ~4% productivity hit OBR associates with Brexit). Beyond trade, the EU’s larger bargaining clout in global trade deals is also noted: as part of the EU, the UK benefited from over 40 trade agreements with third countries (many of which have only been partially replicated post-Brexit). Rejoining would mean UK exporters again enjoy all those preferential terms automatically, instead of the patchwork of deals London is trying to negotiate on its own.
Political Influence and “Having a Say”
Another major pro-EU argument centers on political influence. Inside the EU, the UK had a seat at the table in shaping European-wide decisions that inevitably affect its interests; outside, the UK has found it often must accept or adjust to EU decisions without a voice. Advocates for rejoining argue that Britain’s global influence was amplified by being an EU member. The EU, with its combined economic weight and regulatory power, can set standards (from environmental rules to tech regulation) that smaller individual countries often end up following. As an EU member, the UK was one of the “Big Three” alongside Germany and France, and British diplomats and Members of the European Parliament had significant sway over EU policies. If the UK rejoined, it could once again help steer EU policy on trade, digital regulation, climate change, and more, rather than watching from the outside. This influence is seen as especially important given that many EU rules will affect the UK regardless – for instance, EU product standards must be met by UK companies exporting to Europe. It would be better to “be in the room” and shape those rules than to be a rule-taker, proponents say.
Domestically, rejoining the EU could also ease certain political tensions. For example, it might strengthen the unity of the UK itself. Scotland and Northern Ireland voted to remain in the EU in 2016; Brexit has since fueled calls for Scottish independence and complicated governance in Northern Ireland. If the UK as a whole re-enters the EU, the pressure for Scotland to leave the UK in order to rejoin Europe might diminish. Essentially, UK-wide EU membership could remove one of the grievances that separatists cite (Scotland “being taken out of the EU against its will”). Some unionists argue this would help “take the wind out of the sails” of Scottish independence sentiment and thus preserve the UK’s integrity.
At the European level, Britain’s return is framed by supporters as a boon to the EU’s political heft as well. The EU would regain a member with extensive diplomatic networks, a powerful military, and a global outlook. Many in Europe see the UK as a natural leader on certain issues (for instance, the UK has traditionally had a strong voice on foreign policy and defense, championing a tough line on Russia and a liberal approach to trade). Having the UK back in the EU could bolster the bloc’s collective geopolitical standing – making the EU more of a heavyweight on the world stage. It is telling that European leaders have left the door open: France and Germany in 2023 even floated ideas of “associate membership” to lure the UK back in some form. And the European Commission President Ursula von der Leyen remarked that she personally hopes the UK might one day return, suggesting the “direction of travel” over the long term could lead Britain back into the fold. Such statements indicate that the EU would welcome the UK’s influence again, under the right circumstances. Pro-rejoin voices note that rejoining would allow the UK to help shape the future evolution of Europe – for example, on regulating Big Tech, addressing climate change, or managing migration – rather than sitting on the sidelines as decisions are made largely in Paris, Berlin, and Brussels.
Finally, at the level of global trade talks and standards, the EU’s clout far exceeds the UK’s alone. A rejoined UK would be part of one of the two biggest rule-making entities in the global economy (the EU and US). This means more leverage in negotiations with powers like China or the United States. For instance, if the EU sets data privacy standards (as it did with GDPR) or negotiates trade terms, the UK as a member would benefit from those, whereas outside it often ends up aligning with EU rules anyway (to access the market) but without any control. In summary, the political argument is that EU membership empowers British influence, both within Europe and globally, far more than the “splendid isolation” Brexit was supposed to grant. Britain may have “taken back control” on paper, but in reality being outside has often meant loss of control over the European decisions that matter. Rejoining would remedy that.
Social, Cultural, and Mobility Advantages
Brexit’s reversal is also championed on social and cultural grounds, focusing on the benefits to citizens’ everyday lives and opportunities. Free movement of people is a core EU principle that proponents want to regain. Before Brexit, UK citizens enjoyed the freedom to live, work, study, and retire in any EU country, and vice versa for Europeans in the UK. This enriched the lives of many: young Britons could easily take jobs in Berlin or Barcelona, retirees could spend winters in Spain, and students could participate in the Erasmus exchange program to study at European universities. Since leaving, these freedoms have been lost – UK citizens now face visas and paperwork to move to the EU, and British students have been left out of Erasmus (the UK launched a domestic “Turing Scheme” for exchanges, but it is smaller in scope). Rejoining the EU would restore these individual rights, a significant quality-of-life improvement for the public. It would once again “provide stability and freedom” for people to move across Europe without barriers. Surveys show younger people in the UK overwhelmingly value the ability to travel and work freely in Europe; many have felt that Brexit took away opportunities they expected to have. Rejoining is often framed by youth groups as giving their future back. Indeed, von der Leyen even suggested that the “younger generation” will eventually fix Brexit and restore those connections.
Socially, EU membership also implies being part of a broader European community. Many in the UK feel European and welcomed the cultural exchange that came with membership – from ease of tourism to town twinning to collaborative projects in arts and science. Rejoining would reaffirm common values and collaboration with neighbors. This has intangible benefits: for instance, it could reduce the sense of insularity and mend some of the societal polarization that Brexit induced. Free movement is not just about work – it facilitates cross-cultural understanding, familial ties (there are countless binational families who have struggled with the new residency rules), and the general openness of society. Proponents often mention that over a million Britons were living in other EU countries pre-Brexit (in Spain, France, etc.), and a similar number of EU citizens were long-term residents of the UK. Brexit complicated their lives with new bureaucratic hurdles. Rejoining would resolve the status of EU citizens in the UK and UK citizens in the EU at a stroke, by reinstating their automatic rights.
Additionally, social policy and rights are part of the argument. The EU has a strong framework of protections for workers, consumers, and the environment. Many social liberals in Britain argue that EU membership reinforced things like workers’ rights (paid holidays, maternity leave), anti-discrimination laws, food safety standards, and environmental regulations. While the UK could maintain high standards on its own, pro-EU advocates worry that without the EU “floor,” British governments might be tempted to erode some protections in pursuit of deregulation. Rejoining the EU would lock the UK into a high-standard regime on issues like climate action (via EU climate targets), air and water quality, and product safety. It would also likely recommit Britain to collective scientific and educational initiatives. For example, EU programs such as Horizon Europe (for R&D funding) and Erasmus+ (for education) foster innovation and skills which benefit society and the economy. The UK’s partial absence from these since Brexit is viewed as self-defeating by proponents. Rejoining ensures full participation in these valuable collaborations.
In terms of healthcare and pandemic response, some argue that EU membership has advantages. During COVID-19, the UK went its own way on vaccine procurement (achieving early success), but it missed out on EU schemes for things like medical equipment stockpiles. Future crises might be better handled jointly. Likewise, mutual recognition of professional qualifications in the EU – which ended with Brexit – would return, benefiting professionals (doctors, architects, lawyers) who want the ability to practice across Europe. British retirees would also regain access to EU-wide health insurance via the EHIC system when traveling.
Overall, the social argument is about freedom and quality of life: restoring for UK citizens the myriad everyday benefits of being EU citizens, and for EU citizens the benefits of Britain’s participation. These include freedom of movement, educational and career opportunities, and being part of a diverse multicultural union. The petition for rejoining succinctly mentions providing “stability and freedom” as a benefit of EU membership – freedom here meaning the liberty to move and the stability coming from shared rules and rights that protect individuals.
Diplomatic and Security Advantages
In the realm of foreign policy and security, rejoining the EU is seen by supporters as strengthening both the UK’s and Europe’s ability to handle global challenges. The argument recognizes that today’s threats – from Russian aggression to terrorism to climate change – do not stop at national borders, and that the UK’s security is intertwined with Europe’s. The EU has been developing its security and defense cooperation (though NATO remains primary for collective defense). By rejoining, the UK could participate in and shape the EU’s foreign policy and security initiatives, rather than being a detached partner.
One concrete area is sanctions and response to aggression. The UK and EU have worked closely sanctioning Russia over its war in Ukraine, but this coordination has been ad-hoc. If the UK were an EU member, such actions would be even more unified and possibly more effective, with the UK contributing its significant diplomatic weight to EU common positions. As of 2025, the UK is already aligning with many EU sanctions and foreign policy positions (because divergence would weaken the impact), but without a formal say. Proponents argue it’s logical to formalize this unity by being in the EU’s decision-making structures for foreign policy. They note that Britain remains a major military power and intelligence power in Europe, and its return to the EU would greatly bolster the EU’s capabilities and credibility in foreign affairs. This could lead to a more robust European voice in NATO and vis-à-vis powers like Russia and China. For example, the EU has launched defense cooperation projects (like PESCO); the UK initially stayed out due to Brexit. As a member, the UK could lead such projects, ensuring European defense efforts complement NATO rather than duplicate it.
Diplomatically, supporters highlight the concept of Western unity. With global democracy under pressure and authoritarian powers on the rise, a reunited UK and EU would send a powerful message of unity among the world’s liberal democracies. The United States, traditionally, has preferred a strong, cohesive Europe; President Biden has encouraged UK-EU cooperation (he played a role in nudging an agreement on Northern Ireland). Some international observers argue that Brexit fragmented the Western alliance and that UK rejoining the EU would mend that rift, making the “West” stronger and more coordinated in global fora (e.g., the UN, G7, WTO). In a scenario where the US might elect more inward-looking leadership (e.g., the return of Donald Trump, who was noted for skepticism toward NATO and the EU), Europe standing together including Britain would be even more crucial. Indeed, analysts have suggested that Trump’s potential return in 2025 should accelerate EU-UK security cooperation, given concerns that the US might be a less reliable partner. Rejoining the EU would institutionalize the UK’s cooperation with European neighbors on everything from counter-terrorism to cyber security to energy security.
Another aspect is diplomatic clout in numbers. The EU often negotiates as a bloc on international agreements – whether on climate (like the Paris Accord), Iran’s nuclear program, or trade deals – where its size gives it heft. The UK alone is influential, but the EU with the UK included would represent ~20% of the global economy and a market of 500+ million, which commands attention. A rejoined UK could lead within the EU on global issues it cares about, such as promoting human rights, development aid, and free trade. During its membership, the UK was often a voice for strong EU enlargement and transatlantic alignment; proponents suggest it can play that constructive role again, especially as the EU considers expansion to new members (Ukraine, Western Balkans). With Britain inside, the EU would have a more formidable diplomatic toolkit – including the UK’s extensive embassies network and aid programs working in tandem with the EU’s.
Lastly, intelligence and law enforcement: The EU facilitates extensive data-sharing and cooperation among European police and judicial authorities (through Europol, the European Arrest Warrant, etc.). Post-Brexit, the UK has lost automatic access to some of these tools, making cross-border crime fighting more cumbersome. Rejoining would fully reintegrate the UK into these security frameworks, enhancing the fight against organized crime, human trafficking, and other cross-border threats. British police would benefit from EU databases and vice versa, increasing safety for citizens. Already, both the UK and EU have expressed mutual interest in close security ties; rejoining would remove any legal barriers to the fast extradition of criminals or sharing of criminal data that existed pre-Brexit.
In summary, from a pro perspective, EU membership would amplify the UK’s diplomatic voice and security, allowing it to better address global challenges in concert with allies. Far from losing an independent voice, the UK would gain a louder megaphone by speaking through the EU when beneficial. And it would help ensure Europe remains united in the face of external threats – something proponents view as critical in an era of geopolitical uncertainty.
Legal and Regulatory Alignment
Though perhaps less headline-grabbing than other issues, there are also legal and regulatory arguments for rejoining. The EU operates under a unified legal framework in many areas (the acquis communautaire). Brexit created a divergence: the UK retained a lot of EU law in its books initially, but has begun reviewing or scrapping some of it. Proponents of EU membership contend that much of that legal alignment was beneficial, and that divergence is creating unnecessary costs. For businesses, having to comply with two sets of rules (UK and EU) is burdensome if they trade in both markets. If the UK rejoined, it would streamline regulation – companies would once again follow one set of product standards and rules for the entire EU/UK market, simplifying compliance. This is especially important for industries like pharmaceuticals, chemicals, aviation, and data, where EU regulations are de facto global standards and the UK alone has little to gain by having different rules. By rejoining, the UK would save duplication of regulatory agencies and could participate in EU-wide regulatory bodies (for example, the European Medicines Agency, which the UK hosted in London pre-Brexit). That in turn can speed up processes; rejoin advocates note that cooperation could mean faster access to new medicines and technologies because the UK would be part of the larger EU approval system rather than doing everything separately.
Another legal facet is rights and protections for citizens. The EU’s legal order, overseen by the Court of Justice in Luxembourg, offers avenues of redress and enforces certain rights (like non-discrimination and data protection) uniformly. UK citizens benefited from being able to appeal to EU law in areas like employment rights and consumer protection. Rejoining would restore that additional layer of legal protection. It would also reinstate the European Court of Justice (ECJ) as the ultimate arbitrator of EU law in the UK. While sovereignty-minded critics dislike that, proponents point out that ECJ jurisdiction helps ensure consistent interpretation of rules in every member state, which is essential for a single market. They argue that having the ECJ resolve cross-border disputes is preferable to ad-hoc political arbitration or trade conflicts. Notably, the ECJ played a role in safeguarding the rights of EU citizens in the UK and vice versa after Brexit; pro-rejoin voices suggest that embedding the UK back under the ECJ’s purview in relevant matters would provide greater legal certainty for businesses and individuals operating across borders.
Proponents also argue that rejoining would affirm the UK’s commitment to high legal standards. The EU’s laws on things like food safety (e.g., banning certain additives), environmental law (water quality, air pollution limits), and digital regulation (like the GDPR for data privacy) set a benchmark. Since Brexit, the UK government has considered or enacted changes that diverge – for example, contemplating lowering food import standards or scrapping some EU-derived worker protections. Those in favor of EU membership worry this could lead to a erosion of standards in the long run (a “race to the bottom”). By rejoining, the UK would recommit to those shared high standards and eliminate the risk of regulatory rollback in areas where the EU leads. Essentially, it future-proofs certain rights and norms by binding the UK into the collective legal commitments of the EU.
Finally, there’s a constitutional argument: Brexit and its aftermath have been very consuming for the UK’s governance, sparking legal battles (like the 2019 prorogation of Parliament case) and questions about the devolution settlement (Scotland and Northern Ireland’s place in the Union). Some legal scholars in the pro-EU camp argue that rejoining could provide a stable framework for the UK’s internal constitutional arrangements, because the EU’s multilevel governance gives a voice to regions (Scotland and Wales could engage in EU forums) and lessens some conflicts. While this is a more abstract point, the idea is that the EU framework supports the rule of law and pluralism, which aligns with the UK’s own constitutional values.
In summary, legal alignment with the EU is portrayed as beneficial for consistency, rights, and standards. Rejoining would erase the legal fragmentation that Brexit created, making life simpler for businesses and citizens and ensuring that the UK operates under the robust legal regime that governs its neighbors. It would trade a bit of abstract sovereignty for a lot of practical legal cohesion and clout (since the UK would again help shape EU laws via the Council and Parliament).
Global and Geostrategic Considerations
On the global stage, proponents argue that both the UK and Europe as a whole would be geopolitically stronger if the UK rejoins the EU. We live in a time of great power competition – the United States and China are superpowers, Russia is an aggressive regional power, and new blocs are forming. Europe must remain united to assert its interests and values in this environment. A UK inside the EU makes the Western alliance more unified and creates a bloc of democracies in Europe that is more comparable in weight to the U.S. or China. Geostrategically, a reunited Europe including Britain would command greater respect in trade negotiations, climate negotiations, and in setting international standards.
From the UK’s perspective, proponents say Brexit’s promise of a “Global Britain” has not delivered a clear alternative strategic role. In practice, the UK outside the EU has pivoted only modestly: it has joined the CPTPP and AUKUS, as mentioned, but these do not substitute for the close economic ties and diplomatic coordination it had with Europe. In fact, critics of Brexit note that the UK often appears “caught between” the U.S. and EU on issues – for instance, aligning with Washington on some things, with Brussels on others, sometimes needing to mediate or choosing one side and alienating the other. Rejoining the EU would simplify its strategic posture: the UK would firmly be part of the European pillar of the Western alliance, ideally functioning as a bridge between the US and EU (a role it used to play). This could increase the UK’s relevance to the US (since Washington often coordinates through Brussels on European matters now) and give it more leverage in dealings with China or other rising powers, since it would be backed by the might of the whole EU. The UK alone, while significant, is only ~67 million people and 3% of global GDP; the EU with UK is 500+ million people and around 17-18% of global GDP. Size matters in geopolitics. Advocates say uniting that size with Britain’s diplomatic and military skills is a win-win for projecting influence.
Proponents also note that adversaries benefited from Brexit. It’s widely believed that Russia favored Brexit as it weakened European unity. A House of Commons report even described Russian disinformation efforts around the 2016 referendum. To those who support EU membership, this is telling – if Putin cheered Brexit, then undoing it would be a blow to the strategy of divide-and-rule used by authoritarian regimes. In other words, rejoining the EU could help counter hostile powers that seek to undermine Western cohesion. Instead, a strong, unified UK+EU would present a solid front. In areas like energy security (reducing dependence on Russian gas) or technology (competing with China on 5G, AI standards, etc.), combining efforts is seen as much more effective. The EU has launched initiatives for supply chain resilience and technological sovereignty; the UK could bolster these significantly if it were part of the team.
Another strategic element is climate change and global challenges. The EU often leads in global climate negotiations – it set ambitious emissions targets and has pushed green regulations (like carbon border taxes). The UK has its own climate goals but working within the EU could amplify climate action (indeed, the UK and EU have been aligning their carbon market policies; a recent analysis argued that linking the UK and EU carbon markets would be mutually beneficial). By rejoining, the UK can contribute to and benefit from collective efforts on climate, pandemic preparedness, and other transnational issues that no country can solve alone.
From the perspective of many international actors, UK membership in the EU was historically viewed positively. For example, the United States valued the UK’s moderating, Atlanticist voice in EU councils. Commonwealth countries, too, rarely objected to the UK being in the EU – indeed, some (like India) saw it as an advantage that the UK could advocate for free trade on their behalf within Europe. In 2025, one could argue that numerous allies quietly hope the UK does move closer to Europe again, because it simplifies diplomatic coordination. Pro-rejoin campaigners sometimes cite former U.S. President Obama’s 2016 warning that the UK outside the EU would be at the “back of the queue” for trade deals – the subtext was that the UK’s importance is magnified when it’s part of the larger EU market. While the UK did manage to ink some trade deals post-Brexit, its leverage was limited (the deals with Australia and New Zealand, for example, were on terms that some British farmers criticized as unfavorable). As an EU member, the UK could benefit from the EU’s trade leverage and not have to scramble to replace deals.
In summary, the geostrategic argument is that Britain’s interests and values are best secured by being part of a powerful regional union, rather than attempting to go it alone in a world of continental-scale players. Rejoining the EU would restore the UK to a central place in the “European project,” allowing it to shape the direction of Europe in a way consistent with Western democratic ideals. It would also correct what advocates see as a strategic mistake that left both the UK and EU somewhat diminished. With threats like a potentially hostile Washington (if Trumpism returns) or aggressive Moscow, a Europe that includes London is better prepared to navigate the “far less forgiving world” we face today.
In closing the pro side: All these arguments build the case that the UK should rejoin the EU because it would be better off economically, regain political voice, enrich its society, enhance its security, and contribute to a stronger Europe and West. They anchor these claims in the real experiences since 2016 – noting the economic underperformance, the lost freedoms, and the global upheavals – to assert that Britain’s decision to leave has proven misguided, and that the pragmatic course is to reverse it in due time. By 2025, with Brexit’s disadvantages clearer, the pro-rejoin camp contends that it is in Britain’s national interest, as well as Europe’s, to reunite.
Arguments Against the UK Rejoining the EU
On the other side of the debate, opponents of rejoining the EU believe that the UK should remain outside the Union and continue on its current path. This camp – which includes committed Brexit supporters and others who are skeptical of re-entering – argues that Brexit’s benefits need time to materialize, that sovereignty and self-determination are invaluable, and that rejoining would be risky and potentially harmful. They raise economic, political, social, legal, and strategic points as well, often framing the issue as respecting democratic choice and maximizing the UK’s freedom to act. Below are the major arguments against the UK rejoining the EU, as expressed circa 2025:
Economic Independence and Regulatory Autonomy
Those against rejoining assert that the UK can prosper on its own economically and that the flexibility gained by Brexit is a long-term asset. Economically, they argue, being outside the EU allows the UK to be more agile in striking trade deals and setting regulations tailored to its needs. Rejoining the EU, by contrast, would mean reverting to the EU’s trade policy (where deals are negotiated for all 27 members, often slowly) and accepting EU regulatory standards wholesale. Brexit supporters see value in the UK being able to set its own rules in areas like finance, biotechnology, agriculture, or emerging technologies, without needing EU consensus. For example, the UK has undertaken a more permissive approach to gene-editing in crops and wants to foster a fintech-friendly regulatory environment in the City of London – initiatives they claim might be stifled under one-size-fits-all EU rules. The “Brexit freedoms” slogan encapsulates this: the government under Rishi Sunak has touted how leaving the EU allows Britain to do things like approve medicines faster, adapt its immigration system to national needs, and craft animal welfare laws that might go further than the EU’s. Opponents of rejoining say these are tangible benefits that should not be given up. They point out that the EU can be bureaucratic and slow to change; the UK, on its own, can be more innovative and responsive, whether that’s in regulating AI or signing a quick trade accord with an emerging economy.
Brexit advocates also emphasize the trade deals the UK has been securing globally. While critics note the economic impact of these is small, the anti-rejoin side highlights that the UK has joined the CPTPP (a dynamic Pacific trade bloc) and inked or rolled over deals covering some 70 countries. They argue that over time, these global trade links will grow and that the UK is positioned to benefit from growth in Asia and the Americas. If the UK rejoined the EU, it would have to exit CPTPP (since a country cannot simultaneously be in the EU customs union and an independent trade bloc like CPTPP). That could mean giving up future opportunities in the Indo-Pacific, which Brexit supporters see as shortsighted given that region’s economic rise. Moreover, they argue the EU itself is not very ambitious in free trade nowadays – major EU trade talks (with the US, India, etc.) have stalled due to protectionist lobbies within Europe. The UK outside can be more pro-trade and forge partnerships that the EU as a whole might not. As one example, Britain’s deal with Australia and New Zealand removed nearly all tariffs; some continental farmers would never accept that, which illustrates the freedom to pursue UK-specific economic interests.
A key economic point for rejoin skeptics is also budget contributions. The UK used to be a net contributor to the EU budget – paying in more than it got back (about £8–10 billion net per year in the last years of membership). That money, they argue, can now be spent at home (on the NHS, for instance) rather than sent to Brussels. If the UK were to rejoin, it would presumably have to resume contributions, this time likely without the rebate Margaret Thatcher won in the 1980s (which the EU might not reinstate). Opponents ask: why pay potentially billions a year into EU coffers when the UK could use those funds domestically? They remain skeptical of the economic case that single market benefits outweigh the fee; after all, countries like Norway and Switzerland are affluent without being EU members, suggesting it’s possible to trade with the EU successfully from outside. Indeed, rejoin opponents often prefer the UK to deepen a looser trade relationship (e.g., improving the current Trade and Cooperation Agreement where needed, or perhaps joining the EU’s single market like Norway but without full EU membership obligations). They fear full EU membership would impose undue costs – not just budgetary but also regulatory compliance costs for businesses that serve only the UK market yet would have to follow EU rules.
In summary, the economic argument against rejoining is that the UK should maintain its newly won freedom to set its own economic course. While acknowledging some short-term adjustment costs from Brexit, opponents believe those will be offset by the UK’s ability to become a nimble, globally oriented economy. They caution that rejoining the EU would lock Britain back into a structure that might not suit its particular economic strengths (such as its globally connected financial sector or unique immigration policy preferences). As an example, they highlight how the UK quickly approved and procured COVID-19 vaccines ahead of the EU – a case study, in their view, of how national control can deliver results more efficiently than EU processes. They want to keep that control.
Sovereignty and Democratic Choice
The sovereignty argument is perhaps the most passionately made by anti-rejoin voices. For many who supported Brexit, the principle at stake was that the UK should be a fully sovereign nation, making its own laws and decisions, accountable only to its own voters. They argue that rejoining the EU would mean surrendering that hard-won sovereignty, returning to a situation where EU institutions can impose laws and override national decisions. They point to the fact that EU law was supreme over national law in member states (per the ECJ), and that the UK had to abide by thousands of regulations made in Brussels – some of which, they claim, were not in Britain’s interest. A frequently cited example is EU fishing quotas and rules, which Brexit supporters felt disadvantaged British fishermen. Leaving allowed the UK to “take back control” of its fishing waters (even if in practice the UK government then allocated similar quotas as before). The principle remains powerful: laws should be made by the UK Parliament and interpreted by UK courts, not by a distant European bureaucracy.
Rejoin opponents underscore that Brexit was a democratic decision of the British people, and overturning it would be anti-democratic or at least premature. The 2016 referendum and the subsequent 2019 general election (when a pro-Brexit government won decisively) are seen as clear mandates that “the people” wanted out. Even if polls now show some regret, those against rejoining argue that trust in democracy requires honoring the result for a meaningful period. Immediately moving to rejoin, in their view, would create political turmoil and could be seen as the elite disregarding ordinary voters’ wishes. They often say, “the British people have decided – we must respect that,” adding that political stability depends on not reopening the question so soon. Indeed, as of 2025, even pro-EU politicians like Keir Starmer have taken rejoining off the table, partly to avoid reigniting divisive debates. Rejoin opponents highlight this cross-party acceptance of Brexit as evidence that it’s time to move forward independently, not backwards.
Another sovereignty aspect is border control and immigration. A big slogan of the Leave campaign was “take back control of our borders.” Outside the EU, the UK now can fully determine its immigration policy: it ended free movement for EU citizens and implemented a skills-based visa system equally for all countries. Those against rejoining claim this is a success – they have been able to introduce measures to reduce low-skilled immigration and have more say on who comes in. Although paradoxically net migration has risen to record highs, anti-rejoin figures attribute that to current government choices and argue the principle remains that if and when the UK wants to tighten immigration, it now can (whereas in the EU it couldn’t limit inflows from Europe). Rejoining the EU would restore free movement, which they believe the public would not accept. Immigration was a key concern in 2016; even in 2025, polls show significant portions of the population are wary of large inflows. Thus, opponents say rejoining would likely bring a surge of EU migration (they often cite the possibility of millions of Europeans moving if the UK economy improves, although data doesn’t necessarily support such large numbers). To them, controlling immigration is an essential part of national sovereignty and social cohesion, and it should not be traded away again.
Furthermore, rejoin skeptics argue that as a sovereign country the UK can devise laws tailored to its own values and needs – for instance, in areas like animal welfare or genetic technologies, the UK might choose different approaches than the EU consensus. They note the UK banned live animal exports for slaughter after Brexit and could not have done so under EU free movement of goods rules. They also give examples like crafting agricultural subsidies in a way that fits British farming better now that it’s out of the Common Agricultural Policy. These may seem like niche issues, but collectively they reinforce the notion that Britain’s laws should be made in Britain. The Conservative Party’s 2024 manifesto indeed emphasized safeguarding “post-Brexit freedoms” and explicitly opposed anything that would align with EU laws or give the ECJ jurisdiction again. This stance is representative of a large segment of political opinion that views any step back toward EU alignment as a loss of sovereignty.
In summary, for those against rejoining, it boils down to national self-determination. They believe the UK’s democracy is better served by full control over policy – whether the results are good or bad, at least they are our decisions. They are prepared to accept short-term economic costs as the price of that freedom. To rejoin the EU, in their eyes, would be to reverse the defining choice of recent British history and to subjugate the UK again under a system where it can be outvoted by others. It’s worth noting that even within the EU, the UK often felt it was on the losing side of votes or had to compromise more than it liked. Opponents remember this and warn that if the UK went back, it might have even less influence (some member states might be distrustful or less accommodating of UK opt-outs after the Brexit saga). Thus, sovereignty coupled with the memory of EU constraints fuels the case to stay out.
Social Cohesion and Avoiding Divisiveness
An argument often made against rejoining is that trying to reverse Brexit too soon would re-open bitter divisions in British society. Brexit was and remains a polarizing issue. The years 2016–2019 saw toxic debates, protests, and a sense of political paralysis. Those cautioning against rejoining say that to initiate the process now (in the 2020s) could tear the country apart again. Social cohesion is fragile, and many communities that voted strongly to leave (often in England’s Midlands and North, and in some coastal areas) might feel betrayed or enraged if their vote were effectively overturned. This could fuel the rise of populist or far-right movements exploiting the anger of “Leave” voters who feel the elite ignored them. We see hints of this already: the Reform Party (heir to the Brexit Party) remains opposed to EU ties, and some of its rhetoric claims that the establishment wants to “sell out Brexit.” Opponents of rejoining often invoke this risk – that pushing to re-enter the EU would give demagogues like Nigel Farage new ammunition and could destabilize politics once more.
There’s also the point that few people actively want to relive the Brexit process. Even many Remainers have come to a weary acceptance of Brexit as reality. Polls might show regret, but they also show a lack of appetite for another referendum or a major campaign to rejoin in the immediate future. People have “Brexit fatigue.” Anti-rejoin voices leverage this by arguing that it’s better to move on and focus on making the most of independence, rather than dragging the public through another protracted, contentious EU debate. They often say, “We’ve done Brexit, let’s not keep fighting yesterday’s battles.” The current Prime Minister (as of 2025, Keir Starmer) reflects this sentiment by ruling out rejoining; he instead proposes pragmatic cooperation, precisely to avoid a divisive fight. Thus, opponents claim there is a pragmatic consensus to stick with Brexit, even among former Remain leaders, for the sake of national harmony and political stability.
Socially, they also argue that Brexit has allowed the UK to address voters’ legitimate concerns that had been neglected. For example, high immigration from the EU was linked (rightly or wrongly) in public debate to wage stagnation and pressure on public services. By controlling EU migration, the UK could (in theory) improve conditions for domestic workers and plan infrastructure better. If the UK rejoins and free movement resumes, those pressures might return, potentially inflaming anti-immigrant sentiment even more. Opponents fear a scenario where rejoining without strong consensus leads to a back-and-forth (in which a future government might try to exit again – a kind of “Brexit round 2”). Indeed, continental observers have also noted this: some EU members would worry the UK could be an unreliable member if public opinion is still split. So, anti-rejoiners say, don’t do it until you’re sure the decision would stick – and they argue that time has not yet come, and may never come, because the country remains fundamentally divided on identity lines regarding Europe.
In Northern Ireland, while the topic of rejoining is complex (since NI effectively still follows some EU rules), opponents note that Brexit helped affirm UK sovereignty there, albeit with complications. They would not want to jeopardize the delicate balance of the Windsor Framework by re-entangling in EU membership issues. In Scotland, yes, many want back in the EU, but anti-rejoin voices claim that issue should be resolved by keeping the UK together and making Brexit work for Scotland, rather than taking the UK into the EU just to appease Scottish separatist sentiment (which might persist regardless).
Overall, social stability and respect for the 2016 mandate form a powerful narrative: the country decided to leave; undoing that now would reopen wounds. Better to avoid that turmoil. Many ordinary people, even if they feel Brexit hasn’t worked well, might prefer tweaks to the UK-EU relationship rather than the full drama of re-accession negotiations and another referendum. Opponents often cite this as evidence that their stance is the more realistic and calming one for British society.
Diplomatic Freedom and Global Role Outside the EU
From a foreign policy standpoint, those against rejoining argue the UK has more diplomatic freedom and flexibility outside the EU. They contend that the UK can act as a sovereign nation on the world stage, forming coalitions and initiatives without needing EU consensus (which can sometimes be slow or lowest-common-denominator). One example often given is the UK’s leadership in the AUKUS security pact – negotiating a nuclear submarine deal with the US and Australia, which some continental EU countries were initially unhappy about (France in particular). As an EU member, the UK might have been constrained or pressured to coordinate such moves with Brussels; outside, it freely pursued its security interests in the Indo-Pacific. Similarly, the UK has been able to impose sanctions or take positions (like recognizing Juan Guaidó as Venezuela’s leader in 2019) ahead of or differently from the EU. Opponents frame this as Britain regaining an independent voice in foreign affairs, one that is not automatically bound by EU consensus.
They also claim the UK can serve as a “bridge” or mediator between blocs. For instance, post-Brexit Britain could leverage relationships in the Commonwealth or with the US to broker agreements that the EU as a bloc might not. If it rejoined, it would have to align its foreign policy with the EU’s common positions (which operate by unanimity, but once set, all members are expected to toe the line). Some Eurosceptics point out cases in the past where the UK’s preferences were stymied by EU unity or where the EU took a softer stance than the UK would have (e.g., on China or on sanctions at times). Outside, the UK can be more hawkish or dovish as it sees fit. Indeed, proponents of Brexit in the diplomatic sphere see the UK carving its own path: a permanent UNSC member, G7 economy, leading member of Five Eyes intelligence alliance – not dependent on the EU to exert influence. They often cite that Britain was a global power before it joined the EU, and it can remain so after – arguing that the UK’s global role has “existed since the 16th century and had nothing whatever to do with whether we were inside the EU or outside it,” as one British parliamentarian put it. This view downplays the added value of EU membership to global influence, seeing it as at best one avenue among many, and at worst a “straitjacket” limiting independent initiative.
Opponents also believe the EU’s foreign policy can be ineffective or divided (e.g., internal splits over relations with China, or the slow response in some crises), whereas the UK can respond quickly on its own. For example, in the 2021 Kabul airlift during the Afghanistan withdrawal, the UK coordinated closely with the US and sent troops for evacuations, something that didn’t require an EU framework at all. They suggest that NATO and bilateral alliances are the real backbone of UK security, not EU membership. Therefore, rejoining the EU for security reasons is, in their opinion, unnecessary and could even complicate the primacy of NATO by pulling the UK into EU defense schemes that might duplicate or conflict with NATO (a concern some Americans and Brits have historically had).
From an EU perspective, some member states might not fully trust a returning UK to be cooperative. Eurosceptics in Britain caution that if the UK rejoined, it could face pressure to integrate more (like eventually adopting the euro or joining Schengen), and its attempts to opt-out or shape policy could be met with resentment. They recall how the UK was often on the minority side of issues in the EU (e.g., opposing certain regulations or budget increases) – if it went back in, the UK might find itself constrained by majority voting and unable to wield a veto except in limited areas. Thus, diplomatically, they argue it’s preferable to engage with the EU as an ally and partner (through trade deals, security pacts, ad-hoc cooperation) but not as a member subject to its internal politics. In other words, keep control of our foreign policy and make alliances case-by-case. The UK can still work with the EU when interests align (for example, coordinating sanctions on Russia, as it has done), but it is not bound to EU positions when it might disagree.
In summary, the diplomatic argument against rejoining posits that Britain’s global strategy is best served by freedom of action. The UK can champion free trade, democracy, and security globally on its own terms, and also perhaps play the role of convener between the EU and other powers. They see membership as potentially reducing the UK to just one of many EU voices, whereas outside the EU the UK is a distinct voice that adds to the chorus from its own vantage point. In a sense, they contend that the UK-EU partnership can be healthier with the UK outside – cooperating voluntarily, rather than forced within a single institutional framework that previously led to constant friction.
Legal Sovereignty and Avoiding EU Obligations
Legally, those against rejoining emphasize the importance of the UK’s full legal sovereignty outside the EU. They are relieved that the European Court of Justice no longer has jurisdiction over the UK (except in the very limited context of Northern Ireland’s EU-aligned sector). If the UK were to rejoin, the ECJ in Luxembourg would again have the final say on many legal matters, something Brexiteers fought to eliminate. They argue British courts – up to the UK Supreme Court – should be the ultimate arbiters of UK law. The idea that an EU court could strike down UK legislation or force certain interpretations is an affront to the doctrine of parliamentary sovereignty that lies at the heart of the UK constitution. They give examples: before Brexit, the ECJ issued rulings on everything from employment law to data privacy that the UK had to follow. Opponents of rejoining warn that this would happen again; they specifically mention concerns like the ECJ potentially mandating social policies or economic regulations that a UK government (especially a Conservative or free-market one) might oppose.
Additionally, EU membership comes with numerous obligations that skeptics are loath to resume. These include the possibility of eventually joining the Eurozone (the euro currency) and Schengen (the passport-free travel area). While the UK had opt-outs for these in the past, rejoin opponents note that there is no guarantee the EU would grant the UK the same opt-outs again. In fact, some EU voices have indicated a returning UK might have to accept being a “normal” member with no special treatment. This could mean, for instance, a legal commitment to adopt the euro once convergence criteria are met (as nominally all new members must, aside from Denmark which has an opt-out). The UK public and political class remain strongly against joining the euro – so rejoining the EU under those terms would be practically impossible to sell domestically. The prospect of being forced into “ever closer union” and losing the unique exemptions the UK once had (like the budget rebate and euro opt-out) is a major argument against trying to go back. It implies that rejoining could actually be worse for UK autonomy than the pre-2020 membership was, because the EU might insist on full participation without the old carve-outs.
Opponents also mention EU policies that they view as failures or ill-suited to the UK, which they have no desire to rejoin. One is the Common Agricultural Policy (CAP) – widely criticized for inefficiency and inequitable subsidy distribution; the UK has crafted its own post-Brexit farm support scheme focusing more on environmental outcomes, and some feel it’s better tailored. Another is the Common Fisheries Policy (CFP) – again, contentious in the UK as many fishermen felt it allowed other EU boats too much access and overfishing. Being out of the CFP was seen as a victory for sovereignty and coastal communities (even if benefits have been mixed in practice). Rejoining would put UK fisheries back under EU quotas and rules, which would be very controversial in those communities. Similarly, freedom of movement (as discussed earlier) is seen by many as a policy the UK voted to end; restoring it via EU membership would not only be socially divisive but legally significant (as it confers a suite of rights on all EU citizens in the UK labor and welfare systems).
Another legal dimension is the UK’s ability to forge its own regulations in emerging fields (like AI, fintech, environmental standards) – rejoin opponents assert that the UK can set high standards itself or even go further than the EU if it chooses (for example, the UK has banned some single-use plastics ahead of some EU timelines, and has contemplated stricter online safety laws). They fear that if it re-enters the EU, the UK would be constrained by collective decision-making, which might water down or delay initiatives the UK wants. Essentially, they champion the principle of regulatory competition – the UK can try different approaches outside the EU, which might be more effective or innovative, rather than being bound by a harmonized EU approach that may not fit all.
Lastly, anti-rejoin voices often invoke the concept of the UK’s legal personality on the world stage: as an independent country, the UK can sign its own treaties, sit in international organizations independently (the UK regained its individual WTO seat representation, for example), and can be more agile in responding legally to crises (e.g., developing its own sanctions regime). Rejoining would subsume some of that back into the EU. For instance, in trade negotiations, the UK would no longer negotiate on its own behalf at the WTO or in free trade agreements – it would be represented by the European Commission. For those who see pride and value in the UK’s independent voice, that would be a step backward.
In sum, the legal/regulatory argument is about maintaining the full scope of UK law-making power and avoiding recommitment to certain EU systems that were deemed problematic. Opponents hold that the UK can maintain high standards and cooperate with the EU when desirable without needing to surrender ultimate legal authority to EU institutions. They believe alignment by choice (where beneficial) is fine, but obligation by treaty (as EU membership entails) is not.
Geostrategic Caution and EU’s Issues
Geostrategically, skeptics of rejoining also point out that the EU has its own internal challenges and that the UK might be better off staying out of those. The EU in 2025 faces rising populism in several member states, rule-of-law crises (e.g., in Hungary and Poland), debates over how to handle migration, and the prospect of enlarging to include countries like Ukraine and the Balkans. Opponents argue that the EU is not necessarily a harmonious, stable bloc – it has deep divisions on many issues. They question whether rejoining an EU that might become even more unwieldy with 30+ members is wise. They sometimes portray the EU as a declining project, citing the Eurozone debt problems of the 2010s or the slow decision-making in crises. From this viewpoint, the UK might avoid being entangled in any future EU crises (for example, if the Eurozone were to have another financial meltdown or if political rifts deepen).
They also contend that being outside the EU allows the UK to diversify its partnerships without being tied to a Euro-centric policy. For instance, the UK has strengthened ties with Australia, Japan, and India post-Brexit. If global power is shifting eastward (towards Asia), the UK outside the EU can pivot more freely to Asia-Pacific alliances and trade agreements. Inside the EU, its foreign policy focus would inevitably tilt towards intra-European affairs and consensus with 27 others. Opponents thus see an independent UK as able to be more global in outlook, versus a rejoined UK that would by necessity be more inward-looking to Europe. They often use the phrase “Global Britain” to encapsulate this vision: that Britain can be a globally trading, globally engaged nation that isn’t overly tethered to the continent’s politics.
Finally, they caution that international actors might not uniformly favor a UK return to the EU. For example, the United States – while publicly supportive of EU-UK cooperation – values the UK as a distinct ally with slightly different positions at times. A UK inside the EU might, in some scenarios, align with France/Germany in ways that don’t match US interests. As an example, if the EU took a softer line on China for economic reasons, the UK outside can choose to side more with the US hard line. Inside, it might be compelled to collective positions. Similarly, some Commonwealth nations might worry that a UK back in the EU focuses less on them (a common pre-Brexit sentiment was that EU membership diverted UK attention from historic partners elsewhere).
Of course, these geopolitical calculations can be speculative, but the anti-rejoin side frames it as the UK maximizing its strategic optionality by not being bound in the EU. Britain can be an “honest broker” or a “freelancer” in global diplomacy, which sometimes may deliver results more effectively than being one of a chorus of EU members. They recall instances like the UK’s role in the Iran Nuclear Deal (the UK was part of the EU-led P5+1 talks, but also had its own voice as a permanent UN Security Council member) – they prefer the freedom to operate in multiple formats.
In conclusion, the arguments against the UK rejoining the EU emphasize sovereignty, democratic legitimacy, and flexibility over the promised benefits of EU integration. They acknowledge that Brexit came with costs, but maintain that those can be mitigated without re-entry – for example, through a better trade deal or sectoral agreements with the EU, rather than full membership. They also stress the importance of honoring the referendum and avoiding political chaos. Fundamentally, this side believes the UK can succeed and even thrive by standing apart from the EU, cooperating as a close ally but retaining the full powers of an independent state. Rejoining, in their view, would undercut the very essence of what Brexit achieved: the right for Britons to govern themselves and chart their own course in the world, even if that course diverges from Europe’s. As Prime Minister Sunak’s spokesperson summarized in late 2023, the government’s focus is on “making a success” of the freedoms Brexit gave, not reversing them. Those opposed to rejoining see that as the mandate they must uphold.
Conclusion: The debate over whether the UK should rejoin the EU involves complex trade-offs between economic prosperity and political autonomy, between international influence through collective action and the freedom to act alone, and between reversing a historic decision and respecting democratic outcomes. As of 2025, the UK is navigating a post-Brexit world, seeking a new equilibrium in its relationship with Europe. Proponents of rejoining present a case centered on reclaiming lost benefits and strengthening the UK’s role by returning to the EU, while opponents urge patience and confidence in an independent path, warning against undoing what they see as a restoration of sovereignty. The resolution “The United Kingdom should rejoin the European Union” thus remains deeply contested, with valid concerns and aspirations on each side. Any future shift toward rejoining would require not only practical negotiations (and likely a new referendum), but a durable political and public consensus that, at least in 2025, has yet to fully form.
References (APA style):
BBC News. (2023, June 10). Re-joining EU is our longer term objective – Lib Dems. BBC. https://www.bbc.co.uk/news/uk
Bounds, A., & Parker, G. (2023, November 29). Rishi Sunak dismisses talk of Britain rejoining the EU. Financial Times. (Retrieved via Wikipedia on Potential re-accession of the UK to the EU).
European Commission. (n.d.). Aims and values of the European Union. Retrieved 2025, from https://european-union.europa.eu/principles-countries-history/principles-and-values/aims-and-values_en
House of Commons Library. (2025, March 18). Debate on the UK applying to join the European Union (Debate Pack No. CDP-2025-0067). by S. Fella. https://commonslibrary.parliament.uk/research-briefings/cdp-2025-0067/
Lawless, J. (2025, January 30). 5 years after Britain left the EU, the full impact of Brexit is still emerging. Associated Press News. https://apnews.com/article/brexit-five-year-anniversary-uk-eu-economy-8a8b87fb3ddd9e9ac278469c291f97c1
McBride, J. (2022, March 11). How Does the European Union Work?. Council on Foreign Relations. https://www.cfr.org/backgrounder/how-does-european-union-work
O’Carroll, L., & Crerar, P. (2023, November 29). Sunak rejects von der Leyen’s comments that UK could rejoin EU. The Guardian. https://www.theguardian.com/politics/2023/nov/29/sunak-rejects-von-der-leyens-comments-that-uk-could-rejoin-eu
Smout, A. (2024, December 15). Britain joins trans-Pacific pact in biggest post-Brexit trade deal. Reuters. https://www.reuters.com/world/uk/britain-joins-trans-pacific-pact-biggest-post-brexit-trade-deal-2024-12-15/
The Editors of Encyclopædia Britannica, & Atkins, R. C. (n.d.). United Kingdom. In Encyclopædia Britannica. (Retrieved 2025). https://www.britannica.com/place/United-Kingdom
UK in a Changing Europe. (2020, January 23). Membership 2.0: What the UK rejoining the EU would involve. (LSE Brexit Blog). https://blogs.lse.ac.uk/brexit
Bibliography:
BBC News. (2023, June 10). Re-joining EU is our longer term objective – Lib Dems. BBC. https://www.bbc.co.uk/news/uk (Referenced for Liberal Democrats’ position on rejoining).
Bounds, A., & Parker, G. (2023, November 29). Rishi Sunak dismisses talk of Britain rejoining the EU. Financial Times. Retrieved via https://en.wikipedia.org/wiki/Potential_re-accession_of_the_United_Kingdom_to_the_European_Union (Referenced for von der Leyen’s comments on UK rejoining).
European Commission. (n.d.). Aims and values | European Union. Retrieved June 2025, from https://european-union.europa.eu/principles-countries-history/principles-and-values/aims-and-values_en (Referenced for EU’s aims and values).
Fella, S. (2025, March 18). Debate on the UK applying to join the European Union (House of Commons Library Debate Pack No. 2025-0067). UK Parliament. https://commonslibrary.parliament.uk/research-briefings/cdp-2025-0067/ (Referenced for petition and government responses, and rejoining criteria/opt-outs).
Lawless, J. (2025, January 30). 5 years after Britain left the EU, the full impact of Brexit is still emerging. AP News. https://apnews.com/article/brexit-five-year-anniversary-uk-eu-economy-8a8b87fb3ddd9e9ac278469c291f97c1 (Referenced for Brexit impacts, OBR forecasts, public opinion).
McBride, J. (2022, March 11). How Does the European Union Work? Council on Foreign Relations. https://www.cfr.org/backgrounder/how-does-european-union-work (Referenced for EU institutions and overview).
O’Carroll, L., & Crerar, P. (2023, November 29). Sunak rejects von der Leyen’s comments that UK could rejoin EU. The Guardian. https://www.theguardian.com/politics/2023/nov/29/sunak-rejects-von-der-leyens-comments-that-uk-could-rejoin-eu (Referenced for sovereignty arguments and government stance on Brexit “freedoms”).
Smout, A. (2024, December 15). Britain joins trans-Pacific pact in biggest post-Brexit trade deal. Reuters. https://www.reuters.com/world/uk/britain-joins-trans-pacific-pact-biggest-post-brexit-trade-deal-2024-12-15/ (Referenced for CPTPP membership and impact).
The Editors of Encyclopædia Britannica, & Atkins, R. C. (n.d.). United Kingdom – Relations with the EU. In Encyclopædia Britannica. Retrieved 2025 from https://www.britannica.com/place/United-Kingdom (Referenced for UK-EU historical context and Churchill quote).
UK in a Changing Europe (LSE Brexit). (2020, January 23). Membership 2.0: what the UK rejoining the EU would involve. Retrieved from https://blogs.lse.ac.uk/brexit/2020/01/23/membership-2-0-what-the-uk-rejoining-the-eu-would-involve/ (Referenced for conditions of re-accession and EU member state attitudes).
Euronews (AP copy). (2025, January 31). Five years of Brexit: Is the United Kingdom better off? by R. E. Armstrong. Euronews. https://www.euronews.com/my-europe/2025/01/31/five-years-of-brexit-is-the-united-kingdom-better-off (Referenced for Anand Menon quote, post-Brexit impacts, public opinion and Starmer policies).
Freedom House. (2025). United Kingdom – Freedom in the World 2025. Freedom House. https://freedomhouse.org/country/united-kingdom/freedom-world/2025 (Referenced for description of UK political system and civil liberties).
Carnegie Europe – Krivaite, I., & Nair, P. P. (2025, January 29). Brexit, Bridges, and Barriers: Where Next for EU-UK Relations? Carnegie Endowment. https://carnegieeurope.eu/2025/01/29/brexit-bridges-and-barriers-where-next-for-eu-uk-relations-pub- (Referenced for foreign policy cooperation arguments, Trump factor, and Erasmus request).
Hansard (UK Parliament). (2025, March 13). United Kingdom: Global Position (Lords debate). hansard.parliament.uk (Referenced for historical global role quote).