Floundering Keir Starmer vowed to stay as PM for another eight years today despite a 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'.

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

Sir Keir's bid to stabilise the situation yesterday by bringing veterans Gordon Brown and Harriet Harman back into Government was roundly ridiculed by MPs and ministers.

The premier is now facing a make-or-break moment tomorrow, 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. 

But backbencher Cat West is threatening to launch a 'stalking horse' leadership bid in the morning unless the Cabinet acts - with No10 nervous that anger is so great that she could get the 81 nominations required to spark a vote.

Even loyal MPs are downbeat about the chances Sir Keir can turn his fortunes around, after repeated failed 'reset' attempts.

'Lots of people have done an anti-establishment vote and the answer is Gordon, Harriet and one degree closer to the EU,' one despairing backbencher told the Daily Mail.

'That will really p*** people off in Brexit areas... they are screaming at us and already think we don't listen.'

A former minister said: 'This is going to go down like a cup of cold sick in the Red Wall. He does these speeches and never has anything to say.'

In an interview with the Mirror, Sir Keir was asked if he would lead Labour into the next election and serve a full term in office.

'Yes I will, and I've always said it's a decade of national renewal, where the legacy we inherited was an appalling legacy on all fronts, not just the economy, which was broken,' he said. 

'Public services were broken and actually the situation was worse when we got into office than we thought beforehand.

'There has to be a 10-year project of renewal. If it's to be done properly, that's how it needs to be done.'

Pressed if he would fight any challenge, he said: 'I'm not going to walk away from the job I was elected to do in July 2024.'

So far the Cabinet has held off joining calls for Sir Keir to go - although some including Ed Miliband and Yvette Cooper have offered notably lukewarm support.

Angela Rayner - who is still wrangling with HM Revenue & Customs over unpaid stamp duty - has also stayed silent. She posted pictures on social media last night of her swimming and caked in mud at a charity fundraiser.

Some senior Labour figures believe her prospects have been badly damaged by Reform sweeping the local council in her constituency. She had been pictured canvassing in London during the campaign, which many saw as preparation for a leadership bid.

Ms West shocked Westminster by declaring her intentions to challenge Sir Keir last night. One senior Government aide told the Daily Mail it was a sign that MPs were 'going wild'. 

'It always felt like the most unpredictable element of this weekend - groups of angry backbenchers going wild,' they said. 

There are rumours that supporters of Health Secretary Wes Streeting might be behind the step, as it could be in his interests for Sir Keir to go soon, before Andy Burnham can make a return to the Commons. 

Ms West, MP for Hornsey and Friern Barnet, denied that she wants to thwart Mr Burnham's chances.

'Not at all,' she said. 'I think Andy should be part of the leadership team, and I would expect that any leader will want to appoint Andy, perhaps, to the House of Lords, because you could be a minister in the House of Lords, and he would make a fantastic contribution.

'Whether he can necessarily be the prime minister from the House of Lords, that would be very unusual.'

Ms West said: 'What I'd really like to see is not a leadership election, but for (the Cabinet) to come together and appoint somebody amongst them who can lead us and give us a vision of how we're going to defeat Nigel Farage and the right wing in the coming general election, which could be as soon as possible.'

The backing of 20 per cent of Labour's 403 MPs – a total of 81 - is needed to spark a vote. Ms West acknowledged she only has 10 supporters so far, but argued that could increase quickly.