Jeremy Corbyn is on course to sweep into No 10 after Theresa May failed to deliver on her promise to take the UK out of the EU by March 29, a major polling analysis reveals.

The Conservatives would lose 59 seats in the event of a general election, making Labour the largest party in the Commons, according to an exclusive poll of polls for The Sunday Telegraph.

Iain Duncan Smith, the former Conservative leader, and Amber Rudd, the Work and Pensions Secretary, would be at “high risk” of being voted out.

Experts said the dramatic fall in support was down to anger among Tory voters “at the Government’s failure to deliver Brexit”. Prof Sir John Curtice, ­president of the British Polling ­Council, said Leave supporters had been “drawn back to either Ukip or Nigel Farage’s newly launched Brexit party”.

Separately, amid growing calls for Mrs May to resign, Conservative Party lawyers potentially opened the door for MPs to formally oust the Prime ­Minister within months, with officials advising the influential 1922 ­Committee that the panel could rewrite the rules currently preventing MPs from ­mounting more than one attempt to oust a leader per year.