Mandelson Dossier Exposes Sharp Private Criticisms of Keir Starmer’s Leadership

The UK government has published more than 1,500 pages of documents detailing the controversial appointment and swift dismissal of Lord Peter Mandelson as Britain’s ambassador to the United States, revealing private criticism of Prime Minister Keir Starmer’s leadership and raising fresh questions about vetting processes and political judgment.

The release, described as one of the largest government document dumps in modern times includes thousands of emails, WhatsApp messages, handwritten notes, and official correspondence spanning the decision to appoint Mandelson in late 2024, his short tenure, and his sacking in September 2025. The files were released following parliamentary pressure, with the government framing the move as an unprecedented act of transparency.

Among the most striking revelations are candid messages in which Mandelson, while serving as ambassador, sharply criticised No 10. In a July 2025 exchange with then-Cabinet Office minister Pat McFadden, he described Downing Street as “beleaguered and bereft” and said it required a “complete revamp.” He told McFadden that Starmer’s team “are not led” and suggested the Prime Minister himself appeared unsure of his direction, listing policy reversals on immigration, welfare, and Gaza. In another May 2025 message, Mandelson remarked that “Keir lacks verve as does the Cabinet as a whole.”

The documents also show Mandelson privately criticising the government’s VAT policy on private school fees as “unwise” and offering advice to ministers on issues ranging from AI messaging to gifts for Donald Trump. In a handwritten note to then-Foreign Secretary David Lammy in November 2024, he promised that if appointed, the government would “never regret it.”

Officials had discussed the need for developed vetting, with some warnings about reputational risks linked to Mandelson’s past relationship with the late Jeffrey Epstein. Mandelson was ultimately appointed despite internal reservations, only to be dismissed after further details of that relationship emerged. The files confirm he declined a government request to hand over messages from his personal phone, citing the ongoing Metropolitan Police investigation into allegations of misconduct in public office.

Mandelson, a key architect of New Labour once known as the “Prince of Darkness,” was appointed in December 2024 to strengthen ties with the incoming Trump administration. His tenure ended after nine months. He later resigned from the Labour Party and the House of Lords. He has consistently denied wrongdoing, insisting he did not act for personal gain and is cooperating with police.

Chief Secretary to the Treasury Darren Jones told the House of Commons that the release – running to three volumes, cost the Cabinet Office more than £1 million and that time would be needed to digest its contents. A general debate on the files is scheduled for Wednesday.