Mandelson, 72, was sacked as ambassador in September 2025 following revelations about the depth of his ties to the late sex offender Jeffrey Epstein, with Starmer apologizing for appointing him in the first place, Reuters reported.
But on April 16, new information came to light which showed Mandelson had failed a security vetting process carried out before he was appointed, heaping pressure on the beleaguered prime minister, whose popularity has sunk since he won a huge majority for Labor at a national election in 2024.
Starmer, who had previously told Parliament all due process had been followed over Mandelson, has said it was unforgivable he was not told about the vetting failure until last week. Top Foreign Office official Olly Robbins was consequently sacked.
Starmer said he would “set out the relevant facts” to lawmakers on Monday, while Robbins is due to give evidence in front of a parliamentary committee on Tuesday.
However, Starmer’s opponents have accused the Prime Minister of lying and incompetence, and say his job is no longer tenable.
Liberal Democrats leader Ed Davey said Starmer had shown “catastrophic misjudgment”, while main opposition Conservative Party leader Kemi Badenoch said that, at best, Starmer had been recklessly negligent.
“This has been a tawdry and shaming affair for you and your party, and for this country," Badenoch said in a letter sent to the Prime Minister on April 19.
“Not only have you damaged our relationship with the United States and insulted the victims of the paedophile Jeffrey Epstein, but you have also undermined our national security by giving the highest diplomatic post to an individual that the security services found to be of ‘high concern’,” Badenoch added.
Technology Secretary Liz Kendall said on Sunday that if Starmer had known Mandelson had failed the vetting, he would not have appointed him even though Mandelson had already been chosen to be the next ambassador.
“There is no way that he would have proceeded with that. Whatever the so-called embarrassment, he would have thought that was wrong, and he would not have done it,” Kendall told Sky News.