Britain releases more Mandelson files, reviving Starmer appointment questions

Britain’s latest Mandelson files show a Washington posting that was supposed to project strength instead became a case study in how political appointments are vetted, sold and defended. The second batch of documents, released on Monday, lays out internal emails, texts and other exchanges around Peter Mandelson’s move to Washington and keeps alive a question that reaches beyond Westminster: how much leverage can Britain really claim in the United States if one of its most visible diplomatic jobs is mired in warnings, reversals and leaks?

The new release runs to more than 1,000 pages, with one count putting the total above 1,500 pages, and covers the six months before Mandelson’s appointment plus his seven-month tenure as ambassador. The files were forced out after MPs used a humble address in February to compel disclosure. Some material was withheld because police said publication could prejudice a criminal investigation into alleged misconduct in public office, including allegations that Mandelson passed sensitive government information to Jeffrey Epstein when he was a minister.

The papers deepen pressure on Keir Starmer because they suggest the appointment was politically fraught from the start. Starmer has already said he was “wrong” to appoint Mandelson and has expressed regret, while insisting proper processes were followed. The first tranche, released in March, showed that he had been warned about risks tied to Mandelson’s Epstein connections, his previous resignations from government and his support for closer ties with China. The latest files add fresh detail to that warning trail, including private exchanges between Mandelson, ministers and aides that show the internal calculations behind a decision that was presented publicly as routine.

One of the most damaging documents is a handwritten note from Mandelson to then Foreign Secretary David Lammy saying the government would “never regret” appointing him. Mandelson also challenged security vetting requests by saying he could not list “every foreign national” he had ever met. For a government trying to present itself as disciplined and competent, that is a sharp reminder of how quickly a patronage decision can become a transparency problem.

The political fallout has spread well beyond Mandelson himself. Morgan McSweeney quit in February after advising Starmer to appoint Mandelson, and Tim Allan also left Downing Street as the controversy hardened into a wider complaint about judgment at the top of government. Mandelson, a veteran Labour figure and a former minister, was later sacked as ambassador in September 2025 after the extent of his friendship with Epstein became clearer from U.S. file releases. The latest document dump now makes the broader lesson harder to ignore: in the UK-U.S. relationship, credibility in Washington depends not just on who gets the job, but on how cleanly that choice can survive public scrutiny.