Mandelson files reveal Labour tensions over welfare, tax and Starmer

The second tranche of Mandelson files landed with a blunt snapshot of Labour’s internal strains: more than 1,000 pages of records, and in some accounts more than 1,500, including WhatsApp exchanges between Peter Mandelson and senior ministers. The release followed MPs’ vote earlier in 2026 to force disclosure, after Mandelson was sacked as UK ambassador to the US in September 2025 over leaked emails about his friendship with Jeffrey Epstein.

At the centre of the files is a May 2025 exchange between Mandelson and Pat McFadden, then a Cabinet Office minister and now Work and Pensions Secretary, that lays bare the party’s anxieties over welfare and tax. McFadden wrote: “Every meeting I have is “who can we tax in order to pay benefits to others”,” and warned that Labour MPs were asking the wrong questions about welfare. He also said that a defeat, withdrawal or gutting of the welfare Bill would destroy the prime minister’s authority.

The messages were written after Labour’s poor local election results in May 2025 and the Runcorn by-election defeat, when pressure was already mounting on Keir Starmer’s operation. Mandelson’s own comments were just as stark. He said Starmer lacked “verve” and “panache”, called Downing Street “beleaguered and bereft”, and argued that the government “doesn’t do policy ... well enough” and needed a “complete revamp and infusion of purpose and confidence”.

The political damage was immediate. Conservatives seized on the disclosure to brand Labour “the welfare party”, using the exchanges to sharpen their case that the governing party was locked in an argument with itself over who should pay and who should receive. That attack lands in a week when welfare and tax choices remain central to Labour’s credibility with both its parliamentary party and voters outside Westminster.

The fallout was still rolling through Parliament on Tuesday, with Starmer reported to be chairing Cabinet and MPs due to debate the second tranche of files on Wednesday. The documents do not just capture a row from last year; they show how welfare, taxation and confidence in Starmer’s leadership have remained tightly linked inside Labour’s top ranks.