Mandelson Files Release: What to Expect
The Cabinet Office is set to publish the second tranche of the Mandelson files on Monday, comprising more than 1,000 pages of documents related to Peter Mandelson's appointment as UK ambassador to Washington. This document dump will be the second-largest to the House of Commons after the Chilcot inquiry report into the Iraq war. The disclosures threaten to raise awkward questions over Prime Minister Keir Starmer's judgment in giving Mandelson the UK's most important diplomatic job.
Embarrassing WhatsApp Messages
The release of exchanges from Mandelson's time in Washington could include criticism of the prime minister and awkward WhatsApp messages from ministers trying to impress the now former US ambassador. These may involve group messages with former health secretary Wes Streeting, who has sought to distance himself from Mandelson. Government insiders suggest that Mandelson gave unsolicited advice to ministers on policy areas outside his diplomatic brief.
Omitted Security Vetting Summary
What is not included in the document tranche could be as significant as what is. The released documents are understood to omit a nine-page summary compiled by UK Security Vetting (UKSV). The Guardian previously disclosed that UKSV raised concerns about Mandelson's associations with senior figures in China, Russia, and Israel, and recommended denying clearance. However, reports indicate officials no longer plan to release the summary after the Metropolitan police requested some documents remain confidential.
Lack of Written Mitigations
Multiple sources confirm that the documents contain no written record of the steps Mandelson and top security officials agreed upon for him to receive security clearance. Senior Foreign Office officials told MPs that Mandelson agreed to take certain steps to allay concerns, but the absence of a written agreement casts doubt on these assurances. Some measures addressed commercial conflicts of interest related to Mandelson's stake in Global Counsel, the lobbying firm he co-founded, but these were separate from security mitigations.
Borderline Case Claim Questioned
Olly Robbins, the senior government official sacked for his role in appointing Mandelson after UKSV recommended denial, told MPs that the vetting body considered Mandelson a borderline case and was leaning toward denying clearance. However, no published documents support this claim, and the term has not been used by others who saw the UKSV documents. In fact, a template of the UKSV decision document suggests the opposite.
Mystery of September 2025
One enduring mystery is why Robbins and Ian Collard, the Foreign Office's security chief, made their decision in late January 2025 without reviewing the summary document, relying only on oral briefings. Seven months later, when Mandelson was withdrawn from Washington, they decided to review the summary. Robbins told MPs that queries were made about accessing the document, but the Cabinet Office required a national security justification. However, the Cabinet Office's top civil servant stated that a second request from the Foreign Office's security team led to the summary being handed over, with notes taken by the security chief. It remains unclear what triggered this action and what the notes contained.
