It was a week in British politics that few will soon forget—a week marked by mounting scandal, frantic damage control, and the abrupt downfall of one of Labour’s most prominent political fixers. The resignation of Lord Peter Mandelson as the UK’s ambassador to the United States, following explosive revelations about his friendship with convicted paedophile Jeffrey Epstein, has sent shockwaves through Westminster and left Prime Minister Sir Keir Starmer’s government scrambling to regain its footing just days before a high-profile state visit from US President Donald Trump.
According to reporting by BBC and other outlets, the crisis began simmering long before the public knew. When Mandelson was first considered for the prestigious Washington post in the autumn of 2024, his ties to Epstein were already a matter of public record. The Labour leadership, eager to move beyond traditional diplomatic appointments, saw Mandelson’s experience as a former trade commissioner and his formidable network as assets that could help strengthen UK-US relations in a post-Brexit world. Sir Keir’s chief of staff, Morgan McSweeney, was particularly enthusiastic, reportedly believing there were only two qualified candidates for the role, with Mandelson topping the list.
Yet, even amid the excitement about Mandelson’s potential, there were warning signs. The Cabinet Office’s Propriety and Ethics Team (PET) prepared a file outlining Mandelson’s links to Epstein, which was presented to Sir Keir for review. After reading the file, the prime minister had three pointed questions for Mandelson: Why had he continued his friendship with Epstein after the latter’s 2008 conviction? Had he stayed at Epstein’s Manhattan residence while Epstein was in jail? And was he a founding citizen of an ocean conservation charity that Epstein had backed?
These questions, relayed via McSweeney, were answered by Mandelson in an email. Downing Street sources later described his responses as “economical with the truth.” Mandelson maintained he had not stayed in Epstein’s apartment in 2009 and insisted he had been truthful and frank about his association. Another source confirmed he told Downing Street he had not stayed there. However, court documents from 2023 showed Epstein telling his private banker that Mandelson was planning to stay at the property, though Mandelson never explicitly denied or confirmed if he did. None of these issues, nor the continued friendship or the charity connection, were newly discovered during the vetting process; they had been reported in previous years. But Mandelson’s reassurances were deemed sufficient for his appointment to proceed.
Once Mandelson was officially named ambassador, a second, more rigorous “developed vetting” (DV) process was conducted by the Foreign Office. This process, designed to be forensic and thorough—especially for a role as sensitive as UK ambassador to the US—did not flag any new concerns. As one senior figure put it to the BBC, “they must have used the wrong lens.” Downing Street insists it was not made aware of any problems, and the appointment went ahead.
But the calm was short-lived. In early September 2025, investigative reporters at Bloomberg obtained a cache of emails from Epstein’s now-defunct account, including a string of messages exchanged with Mandelson over several years. These emails painted a far more intimate picture of their relationship than previously known. Among the most damaging were supportive notes Mandelson sent to Epstein after his 2008 conviction for soliciting prostitution from a minor. In one message, Mandelson reportedly told Epstein to “fight for early release,” and, on the eve of Epstein’s prison sentence, another read: “I think the world of you.”
As these revelations loomed, Mandelson himself predicted that more damaging information was about to emerge, describing the situation to The Sun as “very embarrassing.” Yet, according to sources, he did not share the contents of the emails with Downing Street and downplayed the significance of the story. When the Bloomberg emails were published on September 10, alarm bells rang through Whitehall. The government immediately sought clarification from Mandelson, but his answers failed to satisfy. That same day, Sir Keir publicly defended Mandelson during Prime Minister’s Questions—a move that now appears ill-advised, given what was to come.
By Wednesday night, after reading the full cache of emails, Starmer and Foreign Secretary decided that Mandelson’s position was untenable. Mandelson, for his part, refused to resign, reportedly insisting that “it would be fine.” But the tide had turned. On Thursday, September 12, 2025, he was formally dismissed from his post.
The fallout has been fierce and immediate. Within Labour, there is growing criticism not only of Mandelson but also of the prime minister’s judgment and of Morgan McSweeney’s role in championing the appointment. Some Labour MPs are openly questioning whether Sir Keir should resign, while others are directing blame at his senior aides. As one party insider put it, “This isn’t over – No 10 is in total denial.” Another called the episode “just another big misstep.”
For Starmer, the timing could hardly be worse. The scandal erupted just as Labour was hoping for an autumn reset, with the party conference looming and a crucial US state visit on the horizon. Instead, the government has been forced into crisis management mode, with the prime minister’s authority visibly undermined by successive personnel scandals—first Angela Rayner, now Mandelson. “Keir is frustrated and a bit angry because he is having to deal with the conduct of others, rather than show what he is trying to do,” one source told BBC. Another added, “He hired someone who didn’t tell him the full truth.”
The episode has also raised uncomfortable questions about the UK government’s vetting procedures. Despite two separate background checks—one by the Cabinet Office, another by the Foreign Office—neither process uncovered the now-notorious emails. Senior Whitehall figures have suggested that a more thorough and forensic investigation could have located the messages, even though they originated from a defunct account. “Either they skipped the process of any basic due diligence, or they did that process and missed the obvious questions,” said one insider. The Cabinet Office and Downing Street have declined to comment further.
As Labour’s annual conference approaches, Sir Keir Starmer is reportedly taking a more hands-on approach to his keynote speech, aware that this moment could define his leadership. Some party figures remain optimistic that fortunes can change quickly in politics, but the mood is undeniably tense. “I don’t see problems that aren’t fixable,” one senior figure said. Yet, as another minister joked after the shocking fortnight: “I keep thinking maybe it’s all a very detailed dream and I’ll wake up. But then no, this is reality, and we just have to get on with it.”
The Mandelson affair has exposed deep vulnerabilities in Labour’s leadership and vetting, and with the world’s eyes on London for President Trump’s visit, the stakes for Starmer and his team have never been higher.
