Sadiq Khan has called on the new Prime Minister to forge closer relations with the European Union after research indicated that rejoining the bloc could boost London's economy by £2.9 billion. The independent study, commissioned by Best for Britain and seen by the Local Democracy Reporting Service, estimates that reinstated EU membership would deliver significant gains in trade, investment, and protection against US tariffs.
Economic benefits of EU membership
The research, conducted by Frontier Economics, calculated the change in Gross Value Added (GVA) under different scenarios. Full EU membership would increase London's GVA by 0.52%, compared to 0.12% for a standalone customs union and just 0.08% for a food and drink deal. The study highlights that EU membership offers the greatest economic advantage for the capital.
A spokesperson for the Mayor of London told the LDRS: “This is yet more proof – as if it was needed - that Brexit has weakened growth, pushed up the cost of living, and left the London and UK economy smaller than it would otherwise have been. It has been an act of enormous economic self-harm for the UK.”
Political reactions and government stance
The research comes as US President Donald Trump imposed tariffs on 60 trading partners, including the UK and EU. The EU has a 10% all-inclusive deal for tariffs, while the UK faces 10% universal tariffs on top of individual duties. The Mayor's spokesperson added: “The Mayor is clear that we need a serious reset in our relationship with the European Union. We should be moving towards closer alignment, including re-joining the customs union and single market and giving the public a say on our long-term future with Europe at the next general election.”
Naomi Smith, Chief Executive of Best for Britain, said: “A global cultural hotspot, bustling trade hub and financial centre, London is unquestionably a thriving world city and a vital engine of UK-wide growth, but it’s still punching far below its weight. As a new Prime Minister, Andy Burnham now has a chance to transform London’s fortunes, put money back into people’s pockets and help business flourish. Both the public and the data are clear: as this research sets out, EU membership is the quickest and the most popular way to supercharge our capital to reach its full potential.”
Support from MPs and public opinion
London MPs have backed the campaign to rejoin the EU a decade after the Brexit vote. Labour's Marsha de Cordova described close cooperation as a “practical route to the growth and security that this country needs.” Liberal Democrat MP for Twickenham Munira Wilson said London's “world-leading sectors” were “paying a devastating price for a broken relationship with Europe,” adding: “It’s time to repair those ties, slash the bureaucracy, and get London's economy firing on all cylinders again.”
London voters overwhelmingly supported remaining in the EU in 2016, with 59.9% voting to remain and 40.1% to leave. Recent YouGov polling shows 61% of voters still support UK membership of the EU, with only 26% opposed. Less than three in 10 support the current UK-EU relationship.
Government red lines remain
Despite the research and political pressure, a government spokesperson reiterated: “We are building a closer and ambitious relationship with our largest trading partner as we work towards the next UK-EU Summit. Our red lines remain clear: we are not rejoining the European Union, and there will be no return to the customs union, the single market or freedom of movement.”
