A disclosure unlike any other
A Humble Address is a binding motion by which the House of Commons can compel the Government to lay papers before it. The Commons passed one on 4 February 2026.
Peter Mandelson was announced as His Majesty’s Ambassador to the United States on 20 December 2024 and took up post in February 2025. On 11 September 2025 he was withdrawn, after the publication of messages about his relationship with the convicted sex offender Jeffrey Epstein. The day before, the Prime Minister had told the Commons that “full due process was followed” in the appointment.
The Government answered in two tranches. Volume I (published 11 March 2026) is the high-level record: the advice to the Prime Minister, the Cabinet Office due-diligence report, the withdrawal decision, and the severance. Volume II (1 June 2026) is the working-level traffic across three parts — vetting correspondence, ministers’ emails and WhatsApps, and the September 2025 crisis-management drafting. The Government’s own methodology note describes the exercise as “the largest ever Government response to a Humble Address.”
These papers are revealing precisely because they were never written to be read in public — emails between Permanent Secretaries, messages between ministers, and the Cabinet Secretary’s private letter to the Prime Minister.
A later disclosure changed the picture. In April 2026 the Government published further documents — and the Prime Minister confirmed to the Commons on 20 April 2026 — showing that UK Security Vetting had recommended Lord Mandelson’s developed vetting be refused, and that the FCDO granted clearance against that recommendation without telling the Prime Minister, the Foreign Secretary or the Cabinet Secretary. See the update above and “The central question” below.
Was “full due process” followed?
In September 2025 the Government said yes. By April 2026 a later disclosure had overtaken that answer on the central point — vetting.
“Appropriate processes were followed.”
“Two actions, the security vetting and the process on conflicts of interest took place after the decision to appoint… The evidence I have reviewed leads me to conclude that appropriate processes were followed.”
The Cabinet Secretary’s letter to the PM, 16 Sep 2025. It said vetting was “complete… before he took up post” — but did not disclose that UK Security Vetting had recommended clearance be refused.
Clearance was granted against a recommendation to refuse it.
UK Security Vetting recommended developed vetting be refused; the FCDO used its discretion to grant it anyway, on 29 January 2025. The decision was not disclosed to the PM, the Foreign Secretary or the Cabinet Secretary. On 20 April 2026 the Prime Minister told the Commons: “I would not have gone ahead with the appointment,” apologised to Epstein’s victims, and ordered a review.
“The PM was not aware of any of this… including that it was even possible to grant clearance against the advice of UKSV.” (Readout, 15 April 2026.) A review by Sir Adrian Fulford has been commissioned, and the FCDO’s power to overrule UKSV has been suspended.
The other strands the September papers revealed still stand: the Epstein risk was flagged before the decision; the PM “expressed a preference for a political appointment”; a reference to Epstein was later edited out of a paper for Parliament; and on departure Mandelson asked for £547,201, settling at £75,000.
Chronology, 2002 & November 2024 – February 2026
Dates are the documents’ own. Each entry links to the exact page of the official PDF on GOV.UK.
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Key documents, in their own words
Thirty-three documents that carry the story, across both volumes and the April 2026 disclosure. Click a page image to enlarge; click “Read on GOV.UK” to open the official source at the right page. Redactions in the originals are shown as [***]; “LPP” marks legal professional privilege. Browse the full index of all 528 documents →
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Themes running through the papers
The decision
A direct prime-ministerial appointment from outside the civil service. The advice set out the risk that a political appointee leaves the PM “more exposed”; the PM preferred that route, with Mandelson the lead candidate, and the Epstein relationship was discussed before the choice was confirmed.
Epstein
The due diligence flagged the Epstein relationship as a reputational risk and even foresaw the National Archives’ release of 2002 records showing Mandelson facilitated an Epstein introduction to a serving Prime Minister. The mitigation was assurances; when fuller messages emerged, the appointment did not survive.
Vetting
The first position was that no vetting was needed because Mandelson is a peer. That was reversed; an expedited Developed Vetting followed the decision to appoint. In April 2026 it emerged that UK Security Vetting had recommended clearance be refused and that the FCDO granted it against that recommendation — a fact not disclosed to the PM, the Foreign Secretary or the Cabinet Secretary, nor in the September 2025 letter. The completed vetting file remains withheld.
Conflicts of interest & China
The start date was managed around a paid Global Counsel engagement at a Greater China conference; the due diligence noted a live lobbying-register investigation and his Russia (Sistema/RTI) links. The Conflict of Interest form is referenced but not disclosed, and officials struck out the claim that the process had “concluded.”
Money & severance
On withdrawal Mandelson opened with a request for the balance of his four-year contract — £547,201 — before settling at £75,000 (pay in lieu of notice plus a special severance payment). The FCDO called the case “unprecedented,” with “no suggestion of misconduct,” and resolved not to publish the detail.
Records, channels & the gap
Sensitive business by personal email and WhatsApp; MI6 warning his circulars could be hacked and leaked; an instruction to limit “the creation of new disclosable evidence”; and a vetting override that, on the Government’s own account, was “not disclosed to anyone outside FCDO and UKSV” until the Humble Address forced the file open. Still missing: the vetting file itself, material reserved for the police investigation, and a personal phone Mandelson declined to hand over.
Who’s who
The principal named figures in the documents (junior officials are redacted in the originals).