New Mandelson Files on US Ambassador Role Set for Release Before Christmas Break

POLICY WIRE — London, UK — A new set of documents pertaining to Lord Peter Mandelson’s tenure as the British ambassador to the United States is scheduled for public release before the holiday season.

This disclosure follows a parliamentary motion in February, where a ‘humble address’ was used to mandate the publication of more than 1,500 pages of records.

While many files have been released, certain documents were previously withheld to prevent interference with an investigation by the Metropolitan Police into claims of misconduct in public office.

Cat Little, the permanent secretary to the Cabinet Office, announced on Thursday that a segment of these restricted files can now be shared without compromising the ongoing police inquiry.

Ms. Little expressed her expectation that the distribution process will be finalized before Parliament breaks for the Christmas recess on December 17.

In formal correspondence with Lord Beamish, the Labour peer who leads the Intelligence and Security Committee (ISC), Ms. Little confirmed that the Metropolitan Police informed the Cabinet Office that these specific documents are safe for public viewing.

She noted that the Cabinet Office is currently preparing the materials for presentation to the House as quickly as possible to satisfy the parliamentary motion.

The permanent secretary explained that the files require a review to determine if redactions are necessary to protect international relations or national security, which would necessitate referral to the ISC.

Members of the ISC will be granted access to the full versions of the files before they are made public, though some details may remain obscured.

Ms. Little further clarified that some records will remain withheld at the request of the Metropolitan Police to protect the active investigation or future legal proceedings.

Those remaining documents will be released once the Cabinet Office determines it can do so without risking the integrity of the case.

A representative for the Metropolitan Police stated that the investigation into the alleged misconduct in public office remains active.

Lord Mandelson served as the UK representative in Washington starting in February of last year, having been appointed by Prime Minister Sir Keir Starmer.

Sir Keir removed Lord Mandelson from the post in September 2025 following the leak of emails showing the peer sending supportive messages while Jeffrey Epstein was facing imprisonment for sex offenses.

A previous release of documents in June revealed an official responsible for security clearances admitting to a lack of familiarity with ‘Strap,’ an enhanced vetting system.

In an internal email regarding vetting requirements for ennobled peers, a Government Security Group member suggested Lord Mandelson might be exempt from certain protocols.

The official noted in the message that he never understood how the system functioned under normal circumstances, let alone in that specific scenario.

In a 2025 communication to Minister Pat McFadden, Lord Mandelson remarked that Sir Keir and the broader Cabinet lacked verve.

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In addition to her letter to Lord Beamish, Ms. Little sent updates to Conservative MP Simon Hoare and Labour MP Dame Emily Thornberry.

Reporting by Policy-Wire (PW)