LONDON — Prime Minister Keir Starmer insisted Monday he would have “never appointed” Peter Mandelson as Britain’s ambassador to the U.S. if he had been aware of the full scale of Mandelson’s connections to disgraced financier Jeffrey Epstein.

In his latest show of contrition, Starmer expressed regret for handing the Labour grandee such a plum job. Mandelson was sacked last week after leaked emails exposed the extent of his friendship with Epstein, even after the latter was charged with sex offenses.

“Peter Mandelson, before he was appointed, went through a due diligence process,” said Starmer to broadcasters. “That’s the propriety and ethics team. He went through a process, and therefore I knew of his association with Epstein.”

The PM added: “But had I known then what I know now, I’d have never appointed him, because what emerged last week were emails, Bloomberg emails, which showed that the nature and extent of the relationship that Peter Mandelson had with Epstein was far different to what I had understood to be the position when I appointed him.”

Leaked emails to Bloomberg showed Mandelson wrote to Epstein “I think the world of you and I feel hopeless and furious about what has happened,” the day before Epstein begin serving time for soliciting sex from a minor in June 2008.

Mandelson said he should “fight for early release” and told Epstein “your friends stay with you and love you.”

The PM said this “went and cut across the whole approach that I’ve taken on violence against women and girls for many years,” and Mandelson’s responses to questions from government officials were not “at all satisfying.”

Just 24 hours before Mandelson’s sacking, Starmer said at prime minister’s questions that “full due process was followed” during Mandelson’s selection last year and he had confidence in him.