Keir Starmer's premiership was in freefall last night as Cabinet ministers urged him to quit.

Dozens of Labour MPs called for the Prime Minister to resign after a last-ditch fightback speech failed to quell a growing mutiny. 

Last night, Labour sources said a delegation of senior ministers had gone to No 10 to tell Sir Keir his time is up.

Home Secretary Shabana Mahmood and Foreign Secretary Yvette Cooper were among those telling him to go, it was reported.

Several key figures in the Government are said to have visited No 10 on Monday night with Defence Secretary John Healey among those urging the PM to quit.

Further face-to-face calls are expected at this morning's Cabinet meeting if Sir Keir refuses to budge.

'It's happening,' said one source. 'The PM has had his say, people have heard him out, but it has not changed minds. The herd is moving.'

Sir Keir warned that a leadership contest on the eve of tomorrow's King's Speech would plunge the Government and Britain into chaos.

But last night leading figures including Health Secretary Wes Streeting and Greater Manchester mayor Andy Burnham were privately canvassing supporters.

Financial markets took fright at the prospect of a contest driving Labour even further Left, pushing up the cost of government borrowing.

Late last night, 79 MPs had publicly demanded that Sir Keir set out a timetable for his resignation.

Pressure intensified as four ministerial aides quit the Government, saying they no longer believed the PM could turn things round. Another two did not resign, but called on Sir Keir to do so.

But the PM indicated he was determined to fight on, announcing six new ministerial aides to replace those who had called for his resignation.

Joe Morris, aide to Streeting, urged the PM to set out a 'swift timetable' for his departure to allow a new leader to 'regain the confidence of the public'. 

Mr Streeting has privately said he will not launch a direct challenge against Sir Keir, with allies fearing it would damage his chances.

But his campaign is said to be 'ready to go' if the PM faces a tidal wave of calls to resign.

Sir Keir yesterday suggested he would stand and fight against any challenge, saying he would never 'walk away' – raising the possibility that Labour could descend into a bloody civil war.

Ministers are also divided over who should succeed Sir Keir if he is forced out in the coming days. 

While Mr Streeting's supporters want a swift contest, Mr Burnham's allies want Sir Keir to delay his departure to give him time to find a seat at Westminster where he could contest the leadership.

Angela Rayner yesterday called on the PM to drop his opposition to Mr Burnham's return. 

Labour sources claimed Ms Rayner has agreed a 'dream ticket' deal with Mr Burnham which would see her return as deputy prime minister despite an ongoing investigation into her tax affairs.

In a speech to the Communication Workers' Union, Ms Rayner said Mr Burnham 'should never have been blocked', adding: 'It was a mistake that the leadership of our party should put right.'

With Labour MPs divided over who should succeed Sir Keir, any contest would be highly unpredictable.

Mr Burnham is the current favourite, but he could be excluded from running if the PM is forced out in a chaotic process. Allies say he is ready to reveal that a sympathetic north-west MP is willing to step aside to open up a route back to parliament.

But any by-election would take weeks if not months. And with Reform making sweeping gains in Labour's Red Wall, such a contest could be fraught with risk.

Mr Burnham would also have to persuade Labour's ruling National Executive Committee to allow him to stand after it blocked his last bid in February.

Kemi Badenoch said it was 'sad to watch' the PM 'floundering' and warned that replacing him with another Labour politician would make no difference.

'It is not just Starmer,' she said. 'All the pretenders jostling for his job do not have the answers either, because they all believe the same things: more welfare, more state control, more borrowing, more regulation.

'They are busy arguing over who should drive the car, but the truth is they are all heading in the wrong direction.'

Tory chairman Kevin Hollinrake warned that Labour infighting was 'paralysing' the Government. 'The Prime Minister is running out of both time and answers, while members of his own Cabinet plot their leadership bids. Britain cannot afford a Government paralysed by one man's stubbornness.'

Tony Blair's former spin chief Alastair Campbell warned that Labour MPs were 'descending into headless chickenry'.

Sir Keir has been under mounting pressure following disastrous local election results last week which saw Labour lose 1,500 council seats in England and trail in third in Wales and Scotland.

The PM attempted to head off a mutiny yesterday with a speech in which he acknowledged that he had 'doubters' in his own party but insisted he could 'prove them wrong'.

Sir Keir warned the 'chaos' of a leadership contest would cause 'lasting damage' – and said that Labour would 'never be forgiven for inflicting that on our country'. 

He suggested that Labour infighting would only benefit opponents such as Nigel Farage, saying: 'If we don't get this right our country will go down a very dark path.'

But the warning failed to tackle growing anger of his leadership. Within an hour of the PM's speech more backbenchers had started to call for him to go. By the evening the trickle of calls had turned into a flood.

Many Cabinet ministers sat on their hands, with senior figures such as Rachel Reeves and Deputy PM David Lammy offering no public show of support for the PM.

Culture Secretary Lisa Nandy, who was sent out on the airwaves to defend the PM, said he was right to 'acknowledge mistakes' and his own personal unpopularity with voters.

The crisis threatens to cause embarrassment for the King who is due to set out the Government's legislative programme for the coming session at tomorrow's State Opening of Parliament.

Former Tory minister Sir James Cleverly last night said there was a 'genuine question' about the status of the speech if the PM is forced to announce his departure before it is read out.