Keir Starmer is facing a significant challenge today as he struggles to support his top advisor amid a crisis within the Labour Party, fueled by harsh leaks targeting the Cabinet.

The Prime Minister expressed ‘confidence’ in his chief of staff, Morgan McSweeney, after receiving ‘assurances’ that no one from No 10 was involved in the surprising pre-emptive move against Wes Streeting’s alleged leadership ambitions.

Efforts to put the issue to rest come despite the Health Secretary’s vehement response yesterday, accusing Downing Street of engaging in ‘self-destruction’ and calling on the premier to dismiss those responsible.

Speculation has centered on Mr. McSweeney, but Labour insiders worry that Sir Keir’s fate is so intertwined with his aide that he would not withstand McSweeney’s departure.

Last night, the party chairman disclosed that an investigation was underway, and Chancellor Rachel Reeves mentioned this afternoon that she ‘believed’ there would be an inquiry into the leak.

Nevertheless, during a visit to North Wales, Sir Keir effectively dismissed the likelihood of such an inquiry taking place.

Asked if he had confidence in Mr McSweeney, he said: ‘Of course I do. I work closely with my whole team. Our focus is on working for the country.’ 

Sir Keir’s votes of confidence have not always been a lucky charm. He gave the same endorsement to Angela Rayner days before she was forced to resign for underpaying stamp duty in September, saying he was ‘proud’ of his deputy and ‘talking her down’ was ‘a big mistake’. 

The premier also memorably voiced ‘confidence’ in Lord Mandelson at PMQs that month, despite a backlash at his links with Jeffrey Epstein. Shortly afterwards he was relieved of his duties as US ambassador.  

Keir Starmer (pictured in North Wales with Rachel Reeves and Welsh Secretary Jo Stevens today) is struggling to contain mounting pressure to turf out No 10 aides behind brutal briefing against the Cabinet 

The PM voiced ‘confidence’ in his chief of staff Morgan McSweeney after receiving ‘assurances’ that no-one inside No 10 was involved in the extraordinary pre-emptive strike against Wes Streeting’s alleged leadership manoeuvring 

Speaking in North Wales this afternoon, Sir Keir said: ‘First, let me be clear that any briefing against ministers is completely unacceptable. That is not a new position for me, it is a position I have adopted ever since I became Prime Minister. I have made it very clear to my team.

‘I have been talking to my team today. I have been assured that no briefing against ministers was done from No 10, but I have made it clear that I find it absolutely unacceptable.’

He added: ‘I have been assured it didn’t come from Downing Street, but I have been equally clear that whether it is this case or any other, I intend to deal with it.’

Asked if he would sack those responsible, Sir Keir replied: ‘I will absolutely deal with anybody responsible for briefing against ministers, Cabinet ministers or any other ministers. I have always said that is the standard that I expect, and that is the standard that I will enforce.’

The PM’s spokesman denied that the process amounted to a ‘whitewash’ saying Sir Keir had made clear that there would be consequences if people did brief. 

Sir Keir apologised to Mr Streeting when they spoke last night for the first time since the crisis erupted. 

At a brutal PMQs, he denied he had ‘authorised’ any barbs against his own ministers. ‘Any attack on any member of my Cabinet is completely unacceptable,’ he said.

Asked by Kemi Badenoch if he had confidence in Mr McSweeney, Sir Keir did not answer, instead saying everyone in government was ‘absolutely focused on delivering for the country’. 

The PM’s press secretary said afterwards that unauthorised attacks would be ‘dealt with’ – but claimed the briefings against Mr Streeting came from outside Downing Street and clarified that Sir Keir did have confidence in Mr McSweeney.

Net Zero Secretary Ed Miliband was sent out to field questions in TV studios this morning.

‘I’ve talked to Keir before about this kind of briefing that happens. As he always says, if he finds the person, he’ll get rid of them, and I absolutely believe he would do that,’ he told Sky News.

Asked if he thought Sir Keir would sack the person, he said, ‘Sure, yeah.’

He also noted that briefing is a ‘longstanding aspect’ of politics and pointed back to there being ‘lots and lots of briefing’ under Sir Tony Blair and Gordon Brown.

‘Look, I think the briefing has been bad, no question. But my message to the Labour Party, though, is quite simple today, which is, we need to focus on the country, not ourselves,’ he told Sky News.

He added: ‘Turbulence is part of the gig, is part of the DNA of being in government.’

A source said Sir Keir apologised to Mr Streeting for the briefing campaign, without going into details. The pair did not discuss Mr McSweeney and agreed to speak again soon.

Mr Streeting declined to revisit ‘yesterday’s news’ when asked during a visit to the Paddington Community Diagnostic Centre in Liverpool.

He said ‘no idea. Don’t care’ to a question on whether the PM was investigating the source of the attacks on him.

Labour Party chairwoman Anna Turley said last night that Sir Keir would conduct an investigation.

She told ITV: ‘He is going to investigate and we’ll see what happens as a consequence of that.

‘But the reality is, he’s absolutely clear, this is not in his name. This is not what he wants to see and he’s determined to drive it out.’

The Labour chair added: ‘He was not aware of this briefing… He’s going to take action in this to make sure it doesn’t happen again.’

Asked about calls for Mr McSweeney to be sacked, Ms Turley dismissed claims he was behind the briefings as ‘tittle tattle’ as she stressed ‘we don’t know who’s responsible’.

Even admirers admit Mr McSweeney – the election campaign architect – could be on ‘borrowed time’. However, one Labour veteran warned ‘Keir will follow’ if his long-time ally has to go.

Leadership rumours have been sweeping Westminster with Labour at historic poll lows, and friends of Sir Keir are concerned he could be dethroned if the Budget – expected to include massive tax hikes – lands badly.

Furious MPs accused No 10 of having ‘lost the plot’, with fingers pointed at his powerful chief of staff Morgan McSweeney

The assault from No 10 was seemingly timed to coincide with Mr Streeting touring broadcast studios yesterday morning for a big NHS announcement.

The Tories accused Sir Keir of ‘machine-gunning’ his own ministers instead of ‘fixing the country’.

Tom Baldwin, Sir Keir’s biographer and known to be a close ally, insisted the PM is ‘going nowhere’.

He told BBC Radio 4’s Today programme that Mr McSweeney needed to focus on his main role instead of briefing journalists.  

‘He is very, very important to Keir Starmer and I suspect he will stay… I think he should stick to doing the job he’s been given, which was chief of staff,’ Mr Baldwin said.