With US President Donald Trump's state visit to the United Kingdom days away, a growing row over Lord Peter Mandelson's links to Jeffrey Epstein has prompted fierce scrutiny of Downing Street's vetting procedures and its handling of the crisis, leaving Prime Minister Keir Starmer's authority under strain.
A government source and senior Labour figures told the BBC that the prime minister and his team were criticised internally for moving too slowly and for publicly defending the ambassador-designate before the full extent of Epstein-related material had been reviewed. The complaint centres on a sequence of checks carried out before and after Mandelson's appointment and on what officials and ministers knew, and when.
According to reports, the Cabinet Office's Propriety and Ethics Team prepared a file for the prime minister during the selection process that noted Mandelson's past friendship with Epstein. The prime minister asked three questions he wanted cleared up: why Mandelson had maintained contact after Epstein's conviction, whether Mandelson had stayed at Epstein's Manhattan apartment while Epstein was incarcerated, and whether Mandelson was a founding backer of an ocean-conservation charity that Epstein supported. Sir Keir's chief of staff, Morgan McSweeney, sent those questions to Mandelson on the prime minister's behalf and received written replies.
Downing Street sources told the BBC they now judge Mandelson's responses were "economical with the truth". Mandelson has told officials he did not stay at Epstein's Manhattan apartment in 2009 while Epstein was imprisoned; court documents later revealed Epstein told his banker that Mandelson would be staying at the property. Neither the cabinet-level file nor the subsequent checks carried out by the Foreign Office, which included a developed vetting (DV) process, reportedly flagged further concerns to No 10.
A Bloomberg cache of Epstein's emails and a so-called "birthday book" entry that described Mandelson as Epstein's "best pal" — and included a photo of the two, with Mandelson in a bathrobe — intensified the controversy this week. Mandelson told The Sun some of the material would be "very embarrassing", but Downing Street sources say he did not share the emails' contents with officials and was initially dismissive of the threat they posed.
The sequence of public and private moves accelerated midweek. The prime minister gave a robust defence of Mandelson during Prime Minister's Questions, unaware, his office says, of the full contents of the newly published material. After further exchanges and the publication of more emails by Bloomberg, No 10 contacted Mandelson and asked for his resignation. Sources say Mandelson attempted to remain in post; by late Wednesday and into Thursday, after senior ministers and officials had read the exchanges, the decision was taken that he would be removed if he would not step down voluntarily.
Downing Street and the Cabinet Office declined to comment for the BBC report. The Foreign Office did not respond to approaches. Some Whitehall insiders told the BBC the vetting processes either failed to ask forensic questions or did not use the correct "lens" in assessing the risks posed by appointing a man who had twice previously resigned from government posts over questions of judgement.
The controversy has put renewed focus on McSweeney, who had been enthusiastic about Mandelson's appointment and who remains a central figure in Sir Keir's team. Some Labour figures defended him as essential to the prime minister's operation; others said the episode had left the party exposed. Internally, allies offered two readings: that the prime minister had been let down twice in quick succession by senior figures who had not prepared him for the fallout, or that he had misjudged the risks of high-profile appointments.
The timing of the row is politically sensitive. Labour senior officials had viewed Mandelson as a potentially effective ambassador in Washington, pointing to his network and role in securing a UK-US trade deal this year and to the apparent ease of his relationship with President Trump. Trump praised Mandelson's "beautiful accent" in public remarks during a recent Oval Office meeting, underlining the perceived diplomatic benefits of the appointment. The state visit was intended to cement the relationship and showcase the new trade arrangements.
Senior party figures say the episode has undercut a hoped-for autumn reset for Labour, forcing the prime minister to spend political capital managing fallout rather than advancing his agenda. Sir Keir spent time at Chequers over the weekend preparing his conference speech, aides said, and was reported to be determined to press on with a string of policy announcements to try to restore momentum.
Opposition MPs and some within Westminster have seized on the episode as evidence of wider operational weaknesses at the centre of government. Others caution that political fortunes can be volatile and that the party may recover if it can deliver substantive policy wins and steady communications in the coming weeks.
The Mandelson affair has also reopened questions about how sensitive diplomatic appointments are vetted and how information from different security and propriety checks is shared across Whitehall and between departments. Whitehall sources told the BBC that messages between Mandelson and Epstein were sometimes held on a defunct email address, complicating searches, though they said locating older material would have been possible with deeper forensic work.
As the state visit approaches, Downing Street faces the immediate task of managing both the logistics of hosting the US president and the political consequences of the scandal. Senior Labour officials signalled they will press ahead with party business at conference and try to put the controversy behind them, while acknowledging that the episode may linger politically.
Laura Kuenssberg, presenter of Sunday with Laura Kuenssberg, summed up the turmoil: "What a week. What a mess," she said, reflecting a wider sense of disbelief in Westminster at events that have unfolded this month.
Downing Street faces scrutiny over the points at which information about Mandelson's past contacts with Epstein was disclosed and assessed, and whether more rigorous checks would have altered the decision to appoint him to one of the government's most sensitive overseas roles. The episode has become the immediate political story in London as ministers seek to steady the government and prepare for the arrival of a US president whose visit was meant to display a high-water mark in bilateral relations.