Prime Minister Keir Starmer declined to confirm whether he personally discussed Lord Peter Mandelson's ties to Jeffrey Epstein before naming him UK ambassador to the United States.
During Prime Minister's Questions, Conservative leader Kemi Badenoch pressed Mr Starmer repeatedly on whether he had phoned or met Lord Mandelson to raise concerns about the convicted sex offender prior to the appointment.
Mr Starmer apologised for the decision to appoint Lord Mandelson and said the appointment process was flawed, insisting reforms had been introduced since.
He stopped short of answering Badenoch's direct query, instead criticising her record on foreign policy.
Badenoch accused the prime minister of delegating key decisions to aides and of avoiding clear answers.
She also suggested the government timed the recent release of Mandelson-related files to reduce scrutiny.
Last week's first tranche of documents, 147 pages made public after a parliamentary vote, included warnings that Lord Mandelson's relationship with Epstein could harm his standing.
Among the papers was a 2019 JP Morgan report noting unusually close ties, and a note that Mandelson reportedly stayed at Epstein's house while Epstein was jailed in June 2009.
Lord Mandelson was removed from the ambassador role last September after fresh information emerged about his links to Epstein.
Mr Starmer has previously said he did not appreciate the full scale of the relationship when he appointed the peer.
The revelations also contributed to a wider leadership shake-up, including the resignation of Mr Starmer's former chief of staff, Morgan McSweeney.
The independent adviser on ministerial standards reviewed the appointment process, and the prime minister says it has been strengthened.
Lord Mandelson insists he did not lie to the prime minister, says he cannot recall being asked about Epstein in face-to-face vetting interviews, and maintains he answered written questions about post-conviction contact truthfully.
The exchange at PMQs leaves lingering questions about who knew what and when, and has renewed calls for greater clarity around vetting and senior appointments.
