Ex-chancellor Rachel Reeves says Britain's future lies inside the EU and names Brussels its 'obvious' ally over Trump

Rachel Reeves, sacked as chancellor by Andy Burnham when he took office, used a speech at Harvard University's Institute of Politics to call Brexit a historic mistake and demand Britain re-enter the EU. She told the Kennedy School on Monday that estimates now put the cost of Brexit as high as 8% of GDP — equivalent to £200bn — and that ignoring that figure was "simply not serious." Her remarks came as Burnham prepares to sign billions of pounds of trade deals with Brussels at a November 20 summit.

Reeves defended her £66bn in tax rises, claiming they saved families up to £800 on mortgage costs by restraining borrowing and cutting interest rates.

She attacked Trump directly, saying his tariffs, military action in Iran and stance on Ukraine had made 'America's allies poorer.'

Burnham's planned deals cover agricultural exports, youth visas and an emissions trading scheme link worth an estimated £17bn boost, or 0.4% of GDP.