Keir Starmer insisted it is 'unforgivable' that nobody told him about Peter Mandelson failing security vetting today as he battles to save his own skin.

The PM said he was 'furious' after he added the head of the Foreign Office to the list of senior figures ousted in the scandal.

But he made clear he had no intention of resigning himself, pledging to come to the House of Commons on Monday to make his case. 

'I was not told he failed security vetting. No minister was told,' Sir Keir said.

The UK's chief diplomat Olly Robbins was effectively sacked last night after it emerged Mandelson was made US ambassador despite the vetting process advising against his appointment.    

Sir Keir - who is in Paris for a summit on the Middle East crisis later - is facing a rising clamour for his own resignation, with even Labour MPs saying his position is 'not credible'. 

Kemi Badenoch said the PM had 'lied' and was 'taking us for fools'. 'All roads lead to a resignation,' she said. Lib Dem leader Ed Davey said the 'buck stops' in Downing Street.

Sir Keir previously stated that Mandelson passed security vetting, and told the Commons that 'due process' was followed. He did not mention the bombshell developments at PMQs on Wednesday.

'That I wasn't told that Peter Mandelson had failed security vetting when he was appointed is staggering,' he said.

'That I wasn't told that he had failed security vetting when I was telling Parliament that due process had been followed is unforgiveable.

'Not only was I not told, no minister was told, and I'm absolutely furious about that.

'What I intend to do is to go to Parliament on Monday to set out all the relevant facts in true transparency, so Parliament has the full picture.'

As the Mandelson furore comes back to haunt Labour again:

• Questions have been raised over when Sir Olly will get a huge payoff, with Mr Jones acknowledging that vetting procedures were followed;
• The outgoing Foreign Office mandarin has been asked to appear before MPs on Tuesday to explain his actions;  
• Whitehall departments have been banned from going ahead with appointments against the advice of vetting - amid suggestions that has happened in other cases;
• Sir Keir has been accused of breaking the ministerial code by not alerting MPs to the vetting issue earlier;
• Foreign Secretary Yvette Cooper did not learn of the situation until a Guardian report emerged yesterday.   

Veteran Labour MP Jon Trickett said: 'It simply doesn't sound credible for Keir Starmer to claim that he was unaware that Mandelson had been denied security clearance.

'If the PM did not know, it raises gravely serious issues about the way we are governed.

'Either way, the excuses coming from Downing Street won't cut it on the doorstep in the run-up to the local elections.'

Earlier, Sir Keir sent out his close ally Darren Jones to shore up his position. He argued it was a 'state failure' and the premier had no intention of resigning. 

The Cabinet minister told LBC: 'Given the nature of the problem here, not just in terms of the appointment, but the position that it has put the Prime Minister and Cabinet ministers in as a consequence of the decision to overrule the recommendation of UK Security Vetting, and the fact that the system even allowed for that to happen in the first place, it's of a scale of a problem that we've not experienced in government before.

'It is beyond unacceptable.'

Asked on BBC Breakfast whether the PM is going to resign, and whether he has either knowingly or unknowingly misled MPs, Mr Jones responded 'no'. 

'The Prime Minister was right… because the security and vetting process had been conducted and the Foreign Office granted what's called developed vetting status to allow for Peter Mandelson's appointment, so he had been through the process and he had been cleared by the Foreign Office to start the role, so the Prime Minister was right about that,' he said.

'What the Prime Minister was not told until Tuesday evening this week was that the Foreign Office's decision to give that developed vetting status, and to appoint Peter Mandelson as ambassador, was against the recommendations of security and vetting officials.'

He told Sky News that even though security officials recommended that Mandelson be refused developed vetting status, he was allowed to see the most sensitive documents. 

But the mood in Labour circles is grim, despite reluctance to move against the PM amidst the Iran war turmoil and looming local elections. 'It's getting worse', one MP told the Daly Mail. 

Another Labour MP told the i: 'I fail to see how Starmer survives this.' 

One unnamed minister told The Times: 'This is a tipping point. There can be no more excuses; we're past apologies and there cannot be another fall person in the form of Olly Robbins. The PM must go.' 

Another minister admitted that the 'safer ground' Sir Keir had found due to the international crisis had gone. 

Sir Keir announced Mandelson as the UK's man in Washington in December 2024. No10 ignored warnings about the peer's friendship with paedophile Jeffrey Epstein, while 'senior figures' in the Foreign Office were said to have 'advised against' giving the role to someone who was twice forced to resign from Cabinet.

The following month, Sir Olly was appointed Foreign Office permanent secretary, assisting then Foreign Secretary David Lammy.

Remarkably, it was only after he had been publicly given the job that Mandelson, nicknamed the Prince of Darkness, faced vetting for it. 

And it emerged yesterday that the UK Security Vetting (UKSV), a division of the Cabinet Office that scrutinises the background of prospective civil servants, turned him down.

Allies of Mandelson have insisted he did not know that UKSV recommended he be refused clearance. It is also not clear why they made the recommendation. 

Faced with a dilemma - given that his appointment had been announced - officials at the Foreign Office invoked rarely used powers to override the recommendation.

Following Mandelson's sacking in September last year - over fresh information about his links to Epstein - the department concealed the failure.

Sir Olly signed off on Lord Mandelson's £75,000 payout after he resigned, arguing it was 'good value for money'.

Ms Cooper, by now Foreign Secretary, and Sir Olly wrote to the foreign affairs committee to say the security vetting was conducted 'to the usual standard'. They added that this had 'concluded with DV clearance being granted by the FCDO'.

It did not mention that the UKSV had denied him clearance. It is not known why Mandelson failed the checks, but the process involves the disclosure of personal information, including financial and sexual history.

Following the peer's departure, Sir Olly was also questioned at a foreign affairs select committee and again failed to disclose the vetting debacle.

Nigel Farage told LBC: 'None of this adds up, the idea they weren't told about the vetting. 

'Remember, in the House of Commons, Starmer actually said that the vetting had told him about the ongoing relationship with Jeffrey Epstein, then outside of the House, in Hastings, he gave a speech in which he said that Mandelson had cleared security vetting.

'They are all over the place on this, it is totally unbelievable and Robbins, he's the sacrificial lamb in an attempt to try and save the Prime Minister, and it just isn't good enough.'