Sir Keir Starmer appointed Lord Mandelson as British ambassador to the US before formal security checks began, Downing Street has confirmed.

The Labour grandee was confirmed as Britain’s representative to the States in December 2024 – and was sacked on Thursday.

But he was given the role before his links to paedophile financier Jeffrey Epstein had been fully vetted.

In December, he had been “lightly questioned” on his relationship with Epstein.

But before the announcement, the Prime Minister himself was handed a two-page file full of publicly available information about his links to Epstein by the Cabinet Office’s ethics team.

Sir Keir’s right-hand man Morgan McSweeney is then said to have emailed Lord Mandelson with three questions directly from the PM.

The Prime Minister was “satisfied” with Lord Mandelson’s answers about the length of his relationship with Epstein went on, why he stayed in his house and his links to an Epstein-backed charity.

The Foreign Office’s formal vetting process, including an in-person interview, only started after his appointment was made public.

That process is said not to have flagged any points of concern.

Government officials said it is standard practice to carry out the full vetting procedure after an appointment has been made.

Then, on Saturday night, Downing Street sources revealed that Lord Mandelson had been “economical with the truth” in his answers to Mr McSweeney’s emails.

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Whitehall sources then turned to blame the Foreign Office for failing to uncover the emails revealed by Bloomberg and The Sun earlier this week.

One senior figure told the BBC that the “developed vetting… ought to have been completely forensic, but they must have used the wrong lens”.

The Prime Minister has since been accused of misleading Parliament when he defended the Labour peer at PMQs.

Bloomberg had sent a 2,000-word email to Lord Mandelson on Monday, which he then sent on to the Foreign Office.

The Foreign Office then sent on the email, which included details of Lord Mandelson and Epstein’s emails, to No10 on Tuesday morning.

Government sources said that Sir Keir was not informed about the exchanges before he defended the ambassador in the Commons.

With Lord Mandelson soon arriving back from Washington DC, the Prime Minister Lord Mandelson STRIPPED of university honours in wake of Epstein revelationshas been warned that the Labour grandee could move to take him down with him.

A long-time party figure said Lord Mandelson was unlikely to go quietly.

“He’s a fighter, not a quitter, and I wouldn’t want to be on the end of Peter Mandelson as a fighter,” they said.

On Wednesday, Mandelson revealed to The Sun that more “very embarrassing” details of his friendship with Epstein would emerge.

Lord Mandelson’s friendship with the disgraced financier was known before his appointment – but damning reports over the past week established that the pair’s relationship continued after the financier’s crimes had come to light.

The peer told the BBC that he “relied on assurances of [Epstein’s] innocence that turned out later to be horrendously false”.

“His lawyers claimed that it was a shakedown of him, a criminal conspiracy. I foolishly relied on their word, which I regret to this day,” Lord Mandelson added.