Speaking at a “community cohesion” event in Sussex, Starmer said there were two parts to Mandelson’s vetting and suggested that the security services were to blame for failing to uncover his links to Epstein.
He said: “There was a due diligence exercise that culminated in questions being asked, because I wanted to know the answer to certain issues. That’s why those questions were asked, the answers to those questions were not truthful.
“There was then, I should add, security vetting carried out independently by the security services, which is an intensive exercise which gave him clearance for the role and you have to go through that before you take up the post.
“Clearly, both the due diligence and the security vetting need to be looked at again. I’ve already strengthened the due process, I think we need to look at the security vetting.”
It is understood that the “due diligence” process involved Starmer asking Morgan McSweeney, his chief of staff, to ask Mandelson about his relationship with Epstein.
Downing Street maintains that Mandelson lied about his closeness with the notorious paedophile, and is pushing for the release of vetting files that Starmer believes will prove his innocence.
It is understood that the security services carried out the vetting process after a request from the Foreign Office, Mandelson’s direct employer.
It is not known what questions were asked or what aspects of Mandelson’s private life were examined.
But the process did not begin until after his appointment had been approved and announced by Starmer, which Whitehall sources believe meant that he would never have been rejected for the position on security grounds.
Politicians generally avoid criticising the security services, which cannot reply to public criticism because of the secret nature of their work.
Starmer’s attempt to shift the blame will likely increase tension with his backbenchers, who believe it was his error of judgment to appoint a man with well-documented links to Epstein.
Before Mandelson’s appointment, it was known that the two men had a close relationship, and had been pictured together on an island near Epstein’s island, Little St James.
It had been reported that Mandelson had stayed at Epstein’s apartment in New York after his conviction for child sex offences in Florida in 2008.
But MPs believe that Starmer and McSweeney pushed ahead with the appointment out of loyalty to Mandelson, who had offered Labour advice when in opposition.
On Thursday, Starmer apologised to Epstein’s victims and praised the work of the Met Police, which is investigating Mandelson separately over allegations of misconduct in a public office.
“The victims of Epstein have lived with trauma that most of us can barely comprehend,” he said. “And they’ve had to relive it again and again. They have seen accountability delayed and too often denied.
“To them, I want to say this: I am sorry. I am sorry for what was done to you. Sorry that so many people failed you.”
Emails appear to show that Epstein sent Mandelson and his husband at least US$75,000 ($125,240), and that the two men frequently sought each other’s advice.
Following the financial crisis, Mandelson appeared to lobby the Treasury on Epstein’s behalf to water down a tax raid on bankers’ bonuses.
He also appeared to give Epstein advance notice that the Brown government was planning a mass sell-off of state-owned assets.
Starmer added that while it had “been known publicly for some time” that Epstein and Mandelson “knew each other”, the peer had answered questions about their relationship that were “intentionally intended to create the impression that Mandelson barely knew Epstein”.
“I had no reason at that stage to think that was anything other than the truth and, therefore, we proceeded,” he said.
“What I learnt in September was that was not the truth. When further emails came to light ... and having asked some further questions, including questions about whether Mandelson received gifts, benefits and hospitality, and the nature of the relationship, I sacked Mandelson from the role.”
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