Alistair Darling’s future as chancellor was looking precarious on Monday after he admitted making “a mistake” over his expenses and Gordon Brown refused to say whether he would be in his job in 10 days’ time.

Mr Darling paid back £668 he wrongly claimed and apologised “unreservedly” but speculation was growing at Westminster that he could become the first chancellor in postwar Britain to be demoted in the middle of a recession.