The British government plans to release additional internal documents concerning the appointment of Lord Peter Mandelson as the United Kingdom’s ambassador to the United States. Cat Little, the permanent secretary to the Cabinet Office, stated on Thursday, Nov. 5, 2026, that a portion of previously withheld files will be made public before the House of Commons begins its Christmas recess on Dec. 17.
The release follows a "humble address" motion passed by Parliament in February, a procedure used to formally request the production of government papers. While more than 1,500 pages have already been released, officials had previously withheld certain documents to avoid interfering with an active Metropolitan Police investigation into allegations of misconduct in public office.
In a letter to the chairs of several parliamentary committees, Little stated that the Metropolitan Police had assessed that specific documents could now be published without prejudicing their probe. However, some materials will remain withheld at the request of the police until the risk to the investigation or any subsequent legal proceedings has passed. Before the new files are released to the general public, they will undergo a review for potential redactions related to national security or international relations.
The release affects the oversight of diplomatic appointments involving Lord Mandelson, who served as the UK’s ambassador to Washington starting in February 2025. Members of Parliament on the Intelligence and Security Committee (ISC) will have access to unredacted versions of the files before they are published more widely.
The scale of this disclosure involves a portion of the files that were excluded from an earlier 1,500-page release. While the exact number of new pages was not reported, the materials involve records from within the Cabinet Office. These documents may clarify the circumstances surrounding Mandelson’s tenure and his September 2025 dismissal by then-Prime Minister Sir Keir Starmer. That dismissal followed the leak of emails showing Mandelson had sent supportive messages to Jeffrey Epstein while Epstein faced sex offense charges.
Previous releases revealed that a security clearance official admitted to being unfamiliar with the "Strap" enhanced vetting system. The upcoming release, expected by mid-December, will determine what additional information becomes part of the public record regarding the vetting process. The Metropolitan Police stated on Thursday that their investigation into alleged misconduct in public office remains ongoing.