[Analysis] 10 years since the Brexit vote, its lasting effect on British politics and the UK-EU relationship.

The shock result of the UK’s voting to leave the EU and subsequent hard exit in 2020, still looms over British politics and the wider UK and EU relationship 10 years later. 

Far from resolving the question the referendum result caused a rupture in the political status-quo, political fragmentation, and reignited separatist movements characterising Britain’s politics in the years since. What caused a majority to vote to leave was then widely attributed to multiple issues, which remain factors salient in British politics a decade later; structural issues that successive governments have attempted to fix.

Various crises such as Covid-19, the Russia-Ukraine war, crises in the Middle-East, economic stagnation, and a multipolar world, have also pushed the EU and Britain to closer cooperation since, albeit in less formal and via some external frameworks. Britain may no longer be in the bloc, however it continues to exert influence on European affairs, particularly on defence. These moments have also reignited calls from both sides of the Channel towards a ‘reconciliation’ of the relationship as both the EU and the UK meet for a mid-term review of the UK-EU Trade and Cooperation Agreement (TCA).

Numerous questions remain as the relationship moves beyond the decade anniversary of the vote. Will Britain apply to rejoin? If so, what are the likely potential political costs? How do the issues that shaped the debate 10 years ago relevant today?

The referendum campaign, what happened

Three major themes stood out, which are immigration, de-industrialisation, and engrained Euroscepticism. 

Immigration was a predominant feature of the campaign with the Leave advocates focussing on net immigration figures. Exit polls confirmed that this issue featured heavily in the consideration of at least a plurality of voters, and may well per Lord Ashcroft’s post-vote analysis have made the difference in the final result in favour of leaving. Groups supporting leave argued from a range that free movement from the EU undermined Britain, pledging leaving would ‘take back control’ and limit immigration levels. While on the remain side smaller groups made some arguments defending it, while the official campaign led by PM David Cameron mostly steered clear.

The leave vote also won largely among former industrialised, working class, and economically deprived communities across the UK. In this vein the Leave campaign itself effectively managed to convince enough voters who were fed up or had lost faith in established politics, that a vote for their option acted in part as a surrogate for that. While the government’s record wasn’t on the ballot, the remain vote performed better among wealthier and younger areas. Stagnant economic growth post-2008 recession, flatlining wage growth, and regional inequalities across the country were largely attributed to explaining the divide in voters who viewed the status-quo as tolerable versus those that wanted to shake it up. Viewed amid a wider backdrop that the PM himself headed up the Remain campaign, this continues to be a compelling narrative.

None of the above can also take away from the intrinsic high levels of Eurosceptism that had long existed among British voters. The EU up until the vote had consistently been a divisive issue among voters and elected officials alike for years. Expressed both in the wider coverage of the EU in popular newspapers (see ‘Up Yours Delors’), to the success of anti-EU and Eurosceptic parties in EU elections. In 2016, to a significant proportion at least, the answer was arguably always going to be in favour of leave. Expressed principally in the Leave campaign’s slogan “Take Back Control”, and their disputed claim the EU membership cost the UK £350mn per week, the question was in their view framed: how do we best claim back ‘surrendered’ sovereignty to Brussels. Even ardent Pro-EU supporters were more mute in their numbers and presence in the political debate up till 2016. The Remain campaign in contrast focussed more on the risks of leaving than any benefits EU membership afforded Britain, thereby arguably forfeiting whatever value EU membership could have to the Leave side.

Overall the referendum, while being about Britain’s EU membership, was partially not about membership at all. Rather the campaign and the outcome speak to a multitude of reasons and views voters had about their country.

The Brexit effect on Contemporary British politics 

Ten years later these issues remain relevant indirectly to the political debate. 

Immigration 

In the decade since net-immigration to Britain increased by a significant factor, mainly from non-EU countries. Predominantly seeing a spike post-Covid and post-Brexit as skilled labour shortages was sourced from largely non-EU countries, first enacted under Boris Johnson’s government. While numbers have come down since and are expected to continue that way, Brexit has at least either spiked or coincided with higher rates. It should be noted that high figures also spiked because of the initial visa scheme for Ukrainians from 2022-24 and Hong Kongers (those under the British National Overseas route to settlement and citizenship); therefore these rates can’t be ultimately be representative of complete ‘foreign sourced’ immigration either.

Whether or not Brexit is the reason for that spike must be seen through various factors. Concerning irregular cross-Channel migration, having left the EU and the Dublin Agreement Britain had no formal migrant returns agreement with EU countries. This likely aggravated the increased numbers seen over the past few years arriving illegally. In an effort to address this, the UK government has signed bilateral agreements with some EU states, which has in part brought rates down. However their effectiveness over the long-term remains an open question as it’s unclear whether these are completely enforceable, a gaps have emerged.

Immigration therefore remains an active and controversial issue. Looking forward to the UK-EU TCA review, the UK is attempting to cap numbers for a mooted Youth Mobility Scheme, likely conscious of the potency this issue invokes politically.  It seems, at least for now, unlikely that domestic political consensus exists in Britain for unrestricted movement of people, bar among parties explicitly pro-EU. Displayed in part by the government’s proactive trumpeting of recently reduced net-migration figures (compared to the post-Covid spike), and of by electoral successes of anti-immigration candidates in recent local, national, and regional elections.

Established politics

While having in part served as a conduit for frustrated voters, anti-system parties have increased their vote share since the Brexit vote. Brexit is often cited by observers to have ‘broken’ the British political consensus that pre-dated it. Among this class the debate spans between whether Brexit was a symptom of an established political order that increasingly felt distant to more voters’ concerns. Or whether Brexit itself is the cause for the fragmentation that followed.

Although mixed in with more specific reasons, anti-system and separatist parties have seen a series of electoral successes since 2016.  Recent election results in Scotland, Wales, and across England demonstrate as such in the successes of Reform (formerly the Brexit Party), the Green Party, Plaid Cmyru, and the SNP. Some have been around and in power for a while, like the SNP in Scotland, and ultimately argue different positions on the EU, however their overall is an appeal to an anti-Labour, anti-Tory (read: anti-former established parties), and general anti-system vote. 

The EU factor has provided room for more radical parties, catering to some degree of voter frustration with the political mainstream, to channel the rising anti-establishment mood. Stagnant economic conditions and average wages since the 2008-9 recession, frustration with Starmer’s government recently, are also cited as contributing factors to voters’ attitudes towards politics. 

Support for EU membership 

Ironically, post-Brexit support for EU membership has increased among British voters. The general trend heads toward rejoining and or expressing regret at Brexit, these remain ultimately only so by a small margin in aggregate. Rejoining only features explicitly in the Liberal Democrats’ party programme but on a staged and slow process, and to a lesser extent in the Green Party’s. Demonstrating that even where this is given voice it’s done so less prominently than other issues. For the SNP and Plaid Cymru, this issue is intrinsically tied to the constitutional status of the UK itself, therefore unique from that of Great Britain-wide parties. Only former oft-touted potential Labour leadership Wes Streeting proposed putting the question to a vote in the party’s next election manifesto. New PM Andy Burnham deprioritised the issue all together in his recent by-election campaign. It equally continues to animate more Eurosceptic parties such as the Conservatives and Reform UK, who critique the government’s mid-term review proposals for closer alignment with the EU. In other words: don’t expect it to be put to a public vote anytime soon.

The Rejoining Dilemma

Why does that state of domestic politics matter? Because it could impact a potential rejoining effort in the future. 

Hypothetically should the British government apply to rejoin off the back of a referendum or election victory mandate, it would unlikely command a domestic cross-party consensus in favour of it. Public perception and opinion among Brexit-leaning voters and parties are, accordingly to polling remains mostly entrenched. A future government would unlikely right now be able to count on the Conservative or Reform party to support whatever agreement it secured with Brussels in such an event. There would, in theory, be nothing to stop a future opposition government either watering that down or leaving all together again. 

It would consequently be likely that any rejoining deal could contain conditions that could be unpalatable to a large section of British political parties and voters, at least for now. Seeking to ‘lock in’ Britain, it wouldn’t be far-fetched to see the EU seeking compromises on Schengen, Eurozone membership, or the rebate, as conditions for rejoining. However a recent remark by the EU’s former Brexit negotiator Michel Barnier indicated it could be granted pre-Brexit conditions, throw this assumption into doubt. Although polls may indicate a growing pro-EU sentiment across British voters, where participation in all policy areas becomes a requirement the picture is somewhat more convoluted. Therefore any rejoining couldn’t be resolved until a consensus emerges in Britain that can at least tolerate a more ‘enhanced’ version of membership.

It would additionally likely be a harder sell to voters to argue alternatively for EEA membership. Having single market access but without the ability to set or form the rules, presents a significant challenge to those supportive. Or viewed from a Eurosceptic perspective, it’s a more significant handover of sovereignty than having voting and veto powers in Brussels coupled with contributions.

Divergence, similarities, and possible joint issues to address in future 

If a future referendum or election gives a British government the mandate to rejoin the EU it would have to take into account some areas where there are similarities but also divergence.

Defence is the one area where the EU and Britain’s interests and goals align, albeit not always in formal structures or in practice. Both several EU states and Britain are members of the Joint Expeditionary Force and the Coalition of the Willing alongside NATO membership. While several EU states have ramped up defence spending, Britain, despite being the continent’s premier defence power alongside France, remains a laggard. Drone attacks during the U.S. and Israeli War with Iran on its bases on Cyprus demonstrate that a gap in capacity versus perceived standing exists. Although defence remains outside the purview of the EU the war in Ukraine combined with the Second Trump Administration’s stance toward European defence, has spurred a more proactive level of EU-wide coordination. The EU’s SAFE scheme is another example, which Britain currently remains locked out of but would become subject to in the event of a rejoining (it can also become a member without rejoining). This issue and slight difference of approach would overall be relatively ‘easy’ to overcome, even if Britain took longer to ramp up defence investment compared to Germany or the EU’s Nordic members. A wider alignment also appears in foreign policy more broadly as defence takes up a larger role in European affairs. 

When it comes to trade practices, the UK and the EU remain mostly aligned. Partially to maintain an open border in Ireland and minimise friction between largely integrated markets. Britain ultimately remains a European country by geography, and therefore any administration would likely in future seek to minimise possible trade frictions. For example, while the EU requires some form of customs checks on imported goods, Britain has largely delayed implementation of its own checks regime in order to maintain an open market to EU exporters. Even though the divorce was tumultuous in the political sphere, the parties, forced largely by overarching interests particular in this domain have come back to realign, such as Rishi Sunak’s government did in 2023 with the Windsor Framework Agreement. 

Gaps have emerged in policy choices between the bloc and the UK in some domains, which can complicate any future alignment. These would overall create further obstacles to overcome in any negotiation, possibly leaving room for either party to exercise a form of ‘veto’ over such a process. 

On AI and tech regulation the EU and Britain have diverged. Where the EU has implemented the AI Act in 2024, Britain hasn’t formally regulated. This gap represents a more fundamental ‘ideological’ difference, in that the EU opts for a track of regulating to protect citizen’s rights, whereas Britain wants to facilitate room for development. This could present an issue as it hosts the world’s third largest amount of AI founding organisations. For Britain future membership would in practise mean ‘adopting’ the AI Act into domestic law via the EU’s direct effect mechanism, whereas for the EU it could mean admittance of a country that hosts organisations that potentially contravene its standards. This difference could also apply to wider divergence on services generally. 

All of the above is before the outstanding issues on fishing rights, which Britain would have to accept EU shared ownership with, agricultural subsidies, freedom of movement of people, and countless other potential flashpoints. Whatever the benefits to be gained from rejoining, there would likely be political costs for governing political parties in Britain. These costs being at least for the near-future, hard to overcome. 

In summary 

Overall it’s unlikely that Britain rejoins the EU in the near-future due to the lack of domestic political will to do so. However overarching issues in which Britain and the EU align, could facilitate the grounds for possible rejoining, if not continued realignment. A rejoining effort would however have to account for the possibility that Britain wouldn’t likely be able to regain membership on pre-2020 terms, which could add hurdles when gaining public and political support for it. Although the referendum was supposed to settle the question, in practice the issues that shaped the campaign and the outcome are salient a decade on. Consequently the relationship across the Channel will remain unsettled as global events push the parties to align. 

Additional points to ask:

1. Will Britain rejoin the EU? If yes, when.
2. How has the EU evolved since Britain’s departure?
3. Can the UK exert some influence on policymaking in Brussels despite not being in the EU?

Additional Readings:

Paul Webb (2026), 10 Years of Brexit.

Sam Fleming and Martin Arnold (2026), Britain’s Hunt for Post-Brexit Economic Model.

UK in Changing Europe, Ten years on (2026): What next for UK-EU Relations?