Sir Keir Starmer's allies believe he is preparing to step down after his support disappeared over the weekend. According to a senior government figure, the prime minister has begun to realise the "game is up" with "quite a bit of movement" among Cabinet ministers in the wake of Andy Burnham’s sweeping Makerfield by-election victory.

His thoughts have now turned to how he could "shore up his legacy," the senior government figure told The Telegraph. One Labour MP - who is usually considered to be a Starmer loyalist - said he believed Sir Keir would announce his departure date as soon as Monday, given that his support among MPs was now down to only a handful of “friends and family”. “There’s no one left. Literally people whose relatives work in No 10 or people who are long-term personal friends of Keir’s are pretty much the only ones left,” they said, describing the act of trying to fight Mr Burnham's path to Downing Street "like trying to fight gravity".

A government figure predicted that "something will have happened by the end of the week," claiming that the prime minister would be in "mass resignation territory" if he did not resign.

Meanwhile, a former loyal MP who was publicly backing Sir Keir as recently as last month said that he believed Sir Keir was “a goner”, adding: “Andy can do it without a contest, he’s got a good story, and is better for building a broad coalition come a general election".

One ally told The Sun newspaper: “I think there is just a 25% chance he fights on now".

Mr Burnham was said to have the support of close to 300 MPs and Sir Keir is being urged by his Cabinet and MPS - including previous loyalists - to set out a timetable for his departure rather than fight a leadership contest.

A total of five senior Cabinet ministers have privately urged Sir Keir to set out a timetable. Heidi Alexander, the Transport Secretary, did so on Friday, while Yvette Cooper, the Foreign Secretary, delivered a similar message. Shabana Mahmood, the Home Secretary, and even old friend Ed Miliband have previously told him to go.

Elsewhere, Jonathan Reynolds, Sir Keir's chief whip, told him on Friday (June 19) that there was a growing desire among backbenchers for an orderly transition of power to Mr Burnham, according to the Financial Times.

Thursday's Makerfield by-election saw a sweeping victory for the outgoing Mayor of Greater Manchester, which was triggered by the resignation of Labour MP Josh Simons to allow Mr Burnham to return to Westminster and position himself for a potential challenge to the party leadership. With a turnout of 58.7%, Mr Burnham won 54.8% of the vote, while Rob Kenyon of Reform came second with 34.5%.

Mr Burnham outperformed previous opinion polls and nearly doubled the majority his predecessor won in 2024.