Prime Minister Sir Keir Starmer defended Lord Peter Mandelson at Prime Minister’s Questions on Wednesday without being aware of the full contents of emails linking the former EU trade commissioner and Labour cabinet minister to convicted paedophile Jeffrey Epstein, the BBC has learned. Officials at Downing Street and the Foreign Office had been alerted to the messages before Mr Starmer stood in the Commons, and Lord Mandelson was sacked as the United Kingdom’s ambassador to the United States shortly before 11:00 on Thursday.

A media enquiry outlining details of the emails was sent to the Foreign Office on Tuesday and passed to No 10, BBC political correspondents said. Sir Oliver Robbins, the permanent under-secretary at the Foreign Office, asked Lord Mandelson about the emails on Tuesday but did not receive a response until Wednesday, according to the reporting. Sources stressed that the prime minister did not know the contents of the messages when he publicly supported Lord Mandelson at Prime Minister’s Questions.

The full emails were published by Bloomberg and the Sun on Wednesday evening. In one message dated the day before Epstein began serving a jail sentence in 2008 for soliciting sex from a minor, Lord Mandelson wrote: "I think the world of you and I feel hopeless and furious about what has happened." He added: "You have to be incredibly resilient, fight for early release... Your friends stay with you and love you." The Foreign Office said in a statement announcing the dismissal that "the emails show that the depth and extent of Peter Mandelson's relationship with Jeffrey Epstein is materially different from that known at the time of his appointment."

Lord Mandelson, who in an interview with the Sun said he felt a "tremendous sense of regret" for having met Epstein and that he "took at face value the lies that he fed me and many others," has also defended parts of his conduct. The BBC earlier reported that the emails had been sent from an old account to which Lord Mandelson no longer had access, a fact officials cited in explaining why the exchanges had not been seen earlier.

The developments follow US congressional disclosures. Documents released by the US House Oversight Committee indicated Jeffrey Epstein paid for Lord Mandelson's travel on two occasions in 2003, totalling more than $7,400. The committee also released an alleged "birthday book" containing messages sent to Epstein on his 50th birthday in 2003, including one from Lord Mandelson in which he described Epstein as his "best pal" and an "intelligent, sharp-witted man," accompanied by photographs of the two men.

The sequence of events has intensified domestic political pressure on Sir Keir and his leadership. Labour MP Clive Lewis, a prominent figure on the party's left, said the prime minister "doesn't seem up to the job" and warned of a "very, very dangerous atmosphere" among Labour MPs. Another Labour MP, Jo White, said the "clock is ticking" for Mr Starmer to improve the party's standing ahead of local elections next May.

Downing Street defended Mr Starmer's actions by saying he had not been aware of the emails' contents when he stood by Lord Mandelson. The appointment had been announced earlier this summer and Lord Mandelson said after his sacking that serving as the UK's ambassador to the United States had been "the privilege of my life."

The Foreign Office's statement and the timing of publication of the exchanges have raised questions about vetting procedures and about what information was available to ministers and advisers during the appointment process. The House of Commons sits for Prime Minister’s Questions every Wednesday at midday, when the leader of the opposition and other MPs subject the prime minister to questioning, a forum in which Mr Starmer had publicly supported Lord Mandelson before the wider circulation of the emails.

Lord Mandelson’s removal leaves the UK without its newly designated ambassador in Washington while both domestic scrutiny and international attention on the case continue. US lawmakers and media attention to Epstein's network have produced documents and claims that have repeatedly renewed public scrutiny of figures who associated with him. British political figures and diplomats involved in the appointment process have declined to comment beyond official statements from No 10 and the Foreign Office.

The episode adds to challenges for Mr Starmer's government as it navigates partisan scrutiny at home and diplomatic responsibilities abroad. It also underscores the transatlantic dimension of inquiries into Jeffrey Epstein's contacts and the scrutiny that can follow from US congressional disclosures.