Rachel Reeves has argued that the UK should return to the European Union, as Brexit has made the country “poorer, weaker and less secure”.

In her first major intervention since leaving the Treasury, Reeves has thrown her weight behind the prime minister’s decision to reopen the conversation surrounding the UK’s relationship with Europe.

“There is a debate to be had about our future relationship with Europe, and I welcome Andy Burnham’s leadership in facing up to this,” Reeves wrote in the Sunday Times.

“No one in the Treasury ever doubted where my instincts were. I do believe Britain’s future lies in the European Union.”

Her words mark a major u-turn for the former chancellor, as she helped craft Labour’s 2024 election manifesto, which ruled out a return to EU membership and said it would make Brexit work.

Making it work

But Reeves’ insisted it is “incumbent on supporters of our re-entry” to make the case for a return to Brussels.

She said, “Demonstrate tangible benefits and… get the next steps right, especially ahead of the UK-EU summit later this month.”

Reeves added that “at a minimum” the government should be looking for confirmation of the youth mobility scheme she has been pushing for since she was in office, and progress towards entry into the Security Action for Europe (SAFE) defence partnership.

Announced last March, SAFE is part of an EU-wide effort to rearm after Russia’s full-scale invasion of Ukraine.

Burnham and the Brexit debate

Burnham’s decision to reopen the Brexit debate has created cracks in the Labour party, including in his own cabinet. He has argued that it is time to consider “option” that will enable Britain to forge closer ties with the European bloc.

The prime minister has named full EU membership, rejoining the single market and rejoining the customs union as potential paths forward.

While Labour MPs were split, the Conservatives have said there is no desire to rehash the Brexit debate, while Reform have said there is no mandate to pursue closer ties.

Burnham has said that any changes would require a mandate at a general election, which is next due by 2029.