Panicking Labour leftwingers have sounded the alarm bell after a plot to oust Keir Starmer could see Wes Streeting end up replacing him. Fears have been raised that backbencher Catherine West’s threat to launch a ‘stalking horse’ challenge to Sir Keir as early as tomorrow could put Mr Streeting – seen as on the Blairite wing of the party – into No10.

Some believe the Health Secretary’s allies want to force a leadership crisis before Manchester mayor Andy Burnham, favoured by many on the Left, can find a way of returning to the Commons. With Mr Burnham out of the way, Mr Streeting would then try to see off the challenge from his other big rival Angela Rayner.

Former shadow chancellor John McDonnell said Ms West was “reflecting the upset in her constituency” but did not have the “right approach”.

“We need to discuss how we go forward and I worry some in shadows want to exploit her concerns and bounce us before we have a proper democratic process,” he said.

Iscomes as a former Labour minister has warned that Sir Keir has “lost the country”. Josh Simons said the Prime Minister is incapable of “rising to this moment” as he called for an orderly handover of power to a new leader.

He is the latest Labour figure to call on the PM to go following the party’s local election drubbing. His withering assessment comes after another ex-minister, Ms West, threatens to launch a leadership challenge against the Prime Minister.

She has suggested that a woman should now lead the party and has urged the Cabinet to take swift action.

But Education Secretary Bridget Phillipson said the Labour MP was “completely wrong” in a sign that the party’s civil war is deepening.

Labour is tearing itself apart after nightmare local election results saw Reform and the Greens seize huge chunks of the party’s heartlands.

Writing in The Times Mr Simons, the Labour MP for Makerfield, said that Labour is “marching towards extinction” and is “stuck in a politics of incrementalism”.

He said that the elections are an “unequivocal judgment that our actions do not meet the moment”. “We constantly talk big, then act small,” he said.

On Starmer, he added: “Putting the people I represent and the country I love first, I do not believe the prime minister can rise to this moment. He has lost the country. He should take control of the situation by overseeing an orderly transition to a new prime minister.”

It comes as Ms West has said women in the Labour Party need to stand against Sir Keir.

She told BBC’s Sunday With Laura Kuenssberg: “I say to the women of the Parliamentary Labour Party, don’t just allow the men to stand.

“I think we need to modernise. I think we’re looking very dated and I think we need to energise our communications and I think we need to repair our relationship with the Civil Service.”

But Ms Phillipson told Sky News’ Sunday Morning With Trevor Phillips: “What I do recognise, however, is that Catherine, like lots of other colleagues, and like lots of candidates who stood in the elections that we’ve just had, are really hurting, really hurting this morning, and I feel that too.

“Friday morning, I felt absolutely sick to the bottom of my stomach about the scale of the defeat that we’d suffered. We got a real kicking from the voters.

“There’s no escaping that, and we have to reflect seriously on that.”

But, she added: “I’ve knocked on doors right across the country and in my own community, as colleagues will have done too and as party members will have done as well.

“And what I heard was not a desire for a leadership contest, for of the Labour Party to spend more time talking among ourselves.

“What I heard loud and clear from voters was their deep sense of frustration that they’d voted for change in 2024, they were hopeful that that change would be delivered, and they don’t feel that we as a party or we as a Labour Government have delivered what they wanted.”

It comes as Sir Keir vowed to stay as PM for another eight years despite the Labour mutiny gathering pace.

As dozens of MPs demand he quits and rivals mull a leadership challenge, the PM insisted he is at the start of a ’10-year project of renewal’.

Sir Keir has tried to stabilise the situation by bringing veterans Gordon Brown and Harriet Harman back into Government.

The premier is now facing a make-or-break moment on Monday, when he has promised a big speech that will explain how he can save Labour from oblivion.

He is expected to talk up his plans to unwind Brexit, a key demand of many London MPs.