2.4.3 – The aims, role and impact of the European Union (EU) on the UK government
Sadiq Khan, the Mayor of London, has called for the Labour Party to shift its position on the European Union. In an interview last week, Khan argued that:
- The UK should rejoin the customs union and single market before the next General Election.
- At the next General Election, the Labour Party should campaign to rejoin the EU.
In June 2016, the British public voted by 51.9% to 48.1% to leave the European Union. The withdrawal – often referred to as Brexit – did not take effect until 31st January 2020, following five years of intense political debate and disagreement over what form it should take. Some favoured a ‘soft Brexit’: an exit from the European Union that would see the UK remain in, or in close alignment with, EU arrangements such as the single market and the customs union.
The single market is a framework that removes barriers between member states so that goods, services, capital and people can move freely. It is built on the “four freedoms”: free movement of goods, free movement of services, free movement of capital (money), and free movement of people. The customs union concerns trade in goods and tariffs – meaning there are no tariffs (taxes) on goods traded between member countries.
Others favoured a ‘hard Brexit’, which would see the UK break away entirely from EU institutions and systems.
In the deal reached with the European Union in January 2020, Britain moved closer to the hard Brexit end of the spectrum. However, subsequent agreements – including the EU-UK Trade and Cooperation Agreement and the Windsor Framework – saw Britain align more closely with EU trading standards in an effort to reduce friction in cross-border trade.
Sadiq Khan is the most senior Labour politician to openly call for Britain to rejoin the EU. He stated that “I see on a daily basis the damage Brexit has done to not just London, but Londoners – the damage economically, socially and culturally.”
Whilst he is a prominent Labour Party figure, as Mayor of London he is not bound by Collective Ministerial Responsibility, giving him more freedom to speak out. Since entering Downing Street, Keir Starmer has worked to repair the previously strained relationship with the EU, driven largely by his stated primary aim of growing the British economy. In May 2025, Starmer agreed a ‘reset deal’ that reduced trade friction by scrapping checks on a number of products. The agreement also extended EU fishing access in UK waters and established a new defence cooperation agreement.
Starmer and Khan have historically enjoyed a close political relationship. Notably, early in his premiership, Starmer publicly defended Khan when he came under criticism from President Trump. Khan’s intervention will nonetheless be an unwelcome distraction for Starmer – a senior Labour figure openly advocating a position at odds with official party policy is rarely convenient. For Starmer, a committed Remainer during the referendum, the question of the single market must be a particularly conflicted one. His instinct may well be to move towards rejoining it; however, doing so would mean embracing the free movement of people – a political gift to parties on the right, who would swiftly frame it as capitulation on immigration.
The Mayor of London occupies a distinctive position in British politics. By virtue of the role, the holder becomes a significant figure within their party – yet their constituency is very different from that of a national leader. Keir Starmer must weigh what is best for the country as a whole, whereas the Mayor’s focus is necessarily on London’s interests. As one of the most diverse and internationally connected cities in the world, London voted overwhelmingly to Remain in 2016 – by roughly 60% to 40%. The Mayor is therefore, in a very real sense, representing the democratic will of his electorate when he calls for closer ties with Europe. This creates an inherent tension in British politics: a city that accounts for roughly a quarter of the country’s economic output voted decisively one way, yet found itself on the losing side of a national vote. Khan’s position is not simply personal conviction – it is, at least in part, a reflection of what Londoners actually want. Whether the rest of the country will eventually come to share that view remains, for now, an open question.