Mandelson files reveal blistering attacks on Starmer and No 10

Peter Mandelson’s private contempt for Keir Starmer and the No 10 operation was laid bare in another 1,000 pages of files that deepen a row over Labour’s judgment, its internal culture and the handling of his appointment as ambassador to the United States.

The second tranche of documents, published on 1 June 2026, pushed the disclosure into what ministers described as one of the largest government releases ever laid before Parliament. Darren Jones told the House of Commons that the Cabinet Office alone spent more than £1 million on the process, underscoring the scale of a political damage-control exercise that has become much bigger than one appointment.

At the centre of the new material is Mandelson’s blunt assessment of the Labour government after its poor local election results in May 2025. In a message to then Cabinet Office minister Pat McFadden, Mandelson said Starmer “lacks verve as does the Cabinet as a whole” and added that the government needed “more panache.” He said Labour’s problems “stem from the top,” described No 10 as “beleaguered and bereft,” and warned that the government did not “do policy, generally speaking, well enough.”

The papers also show Mandelson turning his fire on Labour MPs, relaying complaints that members were asking “who can we tax to pay benefits to others.” Those messages matter because they show a senior Labour figure not simply trading gossip, but diagnosing what he saw as a deeper weakness in the party’s political instincts and policy discipline.

The files widen the focus beyond Westminster sniping. They include exchanges with David Lammy, Pat McFadden, Torsten Bell and Louise Haigh, and one message to Lammy in which Mandelson said he would “never regret it” if appointed ambassador. Another episode captures Mandelson’s frustration over Donald Trump’s request for a red dispatch box with a gold crest and lettering, a scene Mandelson said was something out of “The Thick Of It.” Trump eventually got the box when Starmer presented it to him at Chequers.

The latest release also feeds the broader controversy over how seriously Labour treated warnings about Mandelson’s suitability. Earlier documents had already shown senior officials thought the appointment was “weirdly rushed,” with national security adviser Jonathan Powell among those raising concerns during vetting. The files suggest officials were scrambling to complete the process quickly, while some papers point to confusion over how much Mandelson had to disclose about foreign contacts.

What began as an attempt to strengthen ties with Trump’s White House has instead become a persistent embarrassment for Starmer, reopening questions about who knew what, when they knew it, and whether the government is now trying to contain the fallout from a politically explosive appointment.