Summary

A decade after the 2016 referendum, the mainstream verdict is that Brexit has imposed a modest but lasting economic cost. Britain's Office for Budget Responsibility assumes long-run productivity is about 4 per cent lower than remaining in the EU, and that exports and imports settle around 15 per cent lower. The clearest damage is in goods-trade friction and a lost half-decade of business investment, while services exports held up better than feared. The end of free movement in 2021 tightened labour supply in care, farming and hospitality. Yet the exact size is genuinely contested, hard to separate from Covid and energy shocks, and supporters value regained sovereignty and new trade deals. Brexit is not finished: the 2025 UK-EU reset and the 2026 Gibraltar Agreement show the settlement, and its price, is still being negotiated.

Five Key Takeaways

  1. The OBR's central assumptions, a 4% long-run productivity hit and trade about 15% lower, anchor the mainstream view that Brexit carries a real, continuing cost.
  2. The clearest damage sits in goods trade friction and a lost half-decade of business investment; UK services exports have held up far better.
  3. The end of free movement reshaped labour supply, feeding shortages and price pressure in care, farming and hospitality.
  4. The precise size is genuinely contested, tangled up with Covid, the energy shock and, more recently, the US-led conflict with Iran.
  5. Brexit is not a finished event: the 2025 reset and the 2026 Gibraltar Agreement show the settlement, and its price, is still being negotiated.

What Happened

It is a decade since the United Kingdom voted to leave the European Union. The referendum of 23 June 2016 set in motion a process that formally ended on 31 January 2020, with the trading relationship governed since 1 January 2021 by the Trade and Cooperation Agreement. Ten years on, the Financial Times and others have returned to a deceptively simple question: what has it cost?

The honest starting point is that the answer is genuinely disputed, but the central estimates from Britain's own fiscal watchdog are not. The Office for Budget Responsibility assumes that leaving the single market and customs union will reduce long-run productivity by about 4 per cent compared with remaining, and that both UK exports and imports will settle around 15 per cent lower than they would otherwise have been.

Those numbers describe a slow drag rather than a single dramatic rupture. The OBR judges that roughly two-fifths of the productivity effect had already occurred before the new arrangements even took effect, largely through the investment uncertainty of the referendum years, with the remainder spread across the years that followed.

The story is not only about trade in goods. The end of free movement in January 2021 and a new points-based immigration system reshaped the labour market, cutting off the easy supply of European workers that sectors such as hospitality, agriculture and social care had come to rely on. Business investment, which had grown steadily before 2016, broadly stalled for years afterwards.

The anniversary reckoning is being written in part because Brexit has quietly slipped out of frontline political debate. Both main parties have largely stopped fighting the old war, yet the arrangements struck in its name still shape the economy the new Prime Minister has inherited.

Against that backdrop sits a genuinely new development. In July 2026 the border fence between Spain and Gibraltar came down under the 2026 Gibraltar Agreement, an EU-UK treaty settling one of the last major pieces of post-Brexit business. It is a reminder that, ten years on, the settlement is still being written.

Why It Matters

Brexit has slipped down the list of things politicians want to discuss, but its economic effects run underneath almost every problem the new government faces. When Andy Burnham talks about weak growth, stretched public finances and the cost of living, he is describing an economy whose trend growth the OBR believes is permanently a little lower than it would have been inside the EU.

A 4 per cent hit to long-run productivity sounds abstract. In practice it means a smaller economy, lower wages than there might have been, and less tax revenue to fund public services, all compounding quietly year after year. It is the kind of loss that never produces a single bad headline, because it shows up as an absence rather than an event.

The trade friction is more visible. Exporters, particularly smaller firms, face customs paperwork, rules-of-origin checks and regulatory divergence that did not exist before. Some have simply stopped selling to the EU, their most important market, because the administrative cost outweighs the margin. The 15 per cent assumed fall in trade intensity is the aggregate of thousands of such decisions.

None of this is spread evenly across the country. Regions and industries most exposed to EU goods trade have felt the friction most sharply, which feeds directly into the regional inequality Burnham has promised to address.

Labour supply matters just as directly to daily life. The end of free movement contributed to shortages that fed into higher prices and unfilled vacancies in care homes, farms and restaurants, even as overall net migration from outside Europe rose to record levels. The composition of who comes to Britain changed more than the headline number.

Yet the significance cuts both ways, which is why the debate endures. Supporters argue that regained control over laws, borders and trade policy carries value that no productivity figure captures, and that Britain has struck its own agreements, including deals with India and the United States, that membership would have prevented. Whether those gains offset the measured costs is a political judgement as much as an economic one.

Detailed Analysis

To weigh the economic price fairly, it helps to separate three strands: the trade and investment evidence, the argument over how much of the damage can really be pinned on Brexit, and the live diplomacy, from Gibraltar to the wider reset, that is quietly reshaping the relationship.

The trade and investment drag

The clearest evidence sits in trade and investment. The OBR's assumption that exports and imports will each be around 15 per cent lower in the long run was calibrated against a range of external studies, not plucked from thin air, and the watchdog's own reviews have found trade broadly performing in line with that pessimistic path rather than better.

Goods trade with the EU has borne the brunt. Non-tariff barriers, the checks, certificates and declarations that replaced frictionless single-market access, act like a tax on every consignment. They fall hardest on smaller exporters and on perishable goods, where delay is costly, and they help explain why the number of firms trading with the EU fell after 2021.

The pattern is uneven across firms as well as sectors. Large companies with the resources to build customs teams have coped; the smallest exporters, for whom the paperwork is proportionally heaviest, have been the most likely to retreat. That distributional effect matters, because small firms are precisely the ones an economy relies on for new competition and future growth.

Business investment is the second channel. Research by Bank of England economists found that the referendum result and the uncertainty that followed weighed heavily on corporate investment, which flatlined for years while comparable economies kept growing theirs. Investment is where future productivity comes from, so a lost half-decade of it echoes forward.

Services, though, complicate the gloomy picture. UK services exports, from finance and law to consulting and computing, have held up strongly and in some areas grown, partly because they were less exposed to the border frictions that hit goods. This is one reason the headline damage has been milder than the most alarming pre-referendum forecasts suggested.

Where the evidence is genuinely contested

Here honesty demands caution. Isolating Brexit's effect is unusually hard, because the years since 2020 also brought a global pandemic, a European energy shock triggered by the war in Ukraine, and, more recently, the disruption of the US-led conflict with Iran. Untangling one cause from the others is a matter of judgement, not arithmetic.

Economists have tried. A widely cited approach builds a statistical doppelganger Britain from a basket of similar economies and compares it with the real thing, generating estimates that the UK economy is perhaps 4 to 5 per cent smaller than it would otherwise be. Critics counter that such models are sensitive to which countries are chosen and how the pandemic is handled, and that they risk attributing to Brexit weaknesses, such as sluggish productivity, that long predate it.

There is a respectable counter-case. Some economists argue that trade has proved more resilient than feared, that the predicted exodus of the City of London did not materialise on the scale forecast, and that new trade agreements and regulatory freedoms could yet pay off over a longer horizon than any current dataset captures.

The fair conclusion is not that the costs are imaginary, but that their precise size is uncertain and probably will be for years. The direction of travel, a modest but real drag on trade, investment and productivity, is where most mainstream analysis converges; the exact magnitude, and how much is permanent, is where reasonable people still disagree.

A settlement still being negotiated

Brexit is often spoken of as a finished event, but the past two years show it is an evolving relationship. In May 2025 the previous government held a reset summit with Brussels, agreeing in principle to a veterinary and food-safety deal designed to strip out some of the checks throttling agri-food trade, alongside cooperation on energy, security and youth mobility.

The 2026 Gibraltar Agreement is the most striking recent instalment. The removal of the fence between Spain and Gibraltar in July 2026 resolved one of the thorniest questions left over from Brexit: how to manage the frontier of a British territory bordering the passport-free Schengen zone. Spain's prime minister, Pedro Sanchez, called it the closing of an open wound and the fall of the last European wall; Gibraltar's chief minister, Fabian Picardo, declared that Europe is back.

Not everyone welcomed it. Critics on both the British and Spanish sides framed elements of the deal as a sovereignty concession, a reminder that every step towards smoother relations reopens the argument that split the country in 2016. The economics may point towards reducing friction, but the politics remain raw.

For Burnham's government the lesson is that the Brexit ledger is not fixed. Each new agreement can recover a little of the lost trade or labour flexibility, or can spend political capital reopening old wounds. The economic price Britain pays is, in part, a function of choices still to be made.

What Happens Next

The immediate question is how far the Burnham government wants to push the reset. Closer alignment on food and farming rules, a smoother emissions-trading link and eased arrangements for touring professionals could each shave a little off the friction, without reopening the settled questions of single-market or customs-union membership.

There are limits, and they are political rather than technical. Rejoining either the single market or the customs union is not on the agenda of any major party, and the rise of Reform UK has if anything hardened the caution around anything that looks like reversing the referendum. The government's room for manoeuvre is real but narrow.

Watch the data as much as the diplomacy. The OBR will keep testing whether its trade and productivity assumptions still hold, and any sustained divergence, better or worse, would reshape the fiscal arithmetic the Chancellor, John Healey, must work with. A less pessimistic reading would ease his task; a gloomier one would tighten an already difficult squeeze.

Labour supply is the other strand to follow. With European workers no longer freely available and non-EU migration under political pressure to fall, sectors that depend on lower-paid labour face a lasting adjustment, whether through higher wages, automation or continued shortages. How that resolves will shape prices in shops, care homes and on building sites.

The Gibraltar deal, finally, may prove a template as much as a footnote. It shows that pragmatic, case-by-case fixes to Brexit's rougher edges are possible even when the underlying politics stays divisive, which is likely to be the pattern for years rather than a single grand renegotiation.

Conclusion

Ten years after the vote, the most defensible verdict is a measured one. Brexit has imposed a real and continuing economic cost, concentrated in trade friction, weaker investment and a tighter supply of labour, and captured in the OBR's central assumptions of a 4 per cent hit to long-run productivity and trade roughly 15 per cent lower than it would have been.

But the honest analyst also concedes what is not known. The precise magnitude is genuinely contested, tangled up with a pandemic and successive energy shocks, and services have fared better than the bleakest forecasts implied. Those who value the sovereignty regained will weigh the ledger differently, and that is a legitimate judgement rather than a factual error.

What is clear is that the settlement is not static. From the 2025 reset to the 2026 Gibraltar Agreement, Britain is still negotiating the terms of its departure, and each deal nudges the cost up or down at the margin.

For a Prime Minister who has staked his premiership on growth and the cost of living, that is the practical point. Brexit is no longer a debate to be won or lost so much as a set of frictions to be managed, and how well they are managed will quietly shape how much Britain still pays in the decade ahead.