The Government released thousands of files on Monday relating to Lord Peter Mandelson’s appointment as US ambassador.
The documents included email and WhatsApp exchanges between figures at the heart of Government in the lead up to the controversial appointment, as well as during Lord Mandelson’s time in the job, and in the aftermath of his exit.
Here is a timeline of everything we know about Lord Mandelson’s appointment and the ensuing fallout.
November 18 2024
In what appears to be a gentle lobbying effort to encourage his appointment as ambassador, Lord Mandelson writes to then-foreign secretary David Lammy to say the Government would “never regret” the move, the latest files reveal.
December 20 2024
Prime Minister Keir Starmer says he is “delighted” to announce Lord Mandelson, a former New Labour minister and party grandee, as his choice to be the UK’s ambassador to the US.
January 8 2025
Senior civil servant Sir Olly Robbins is made permanent secretary at the Foreign Office.
January 28 2025
A formal decision to deny Lord Mandelson security clearance is reportedly made by UK Security Vetting (UKSV).
January 29 2025
Foreign Office civil servants grant the peer developed vetting clearance despite the UKSV recommendation that this should be denied. This enables him to see secret information in his new role.
February 2025
Lord Mandelson takes up the appointment and attends a White House welcome reception.
July 2025
Texts from the latest disclosures reveal Lord Mandelson said a “long, hysterical message” from Wes Streeting about Israel “reflects pretty badly on his maturity”.
In a WhatsApp message previously released by Mr Streeting, the then-health secretary discussed the recognition of a Palestinian state with Lord Mandelson.
But the peer separately told senior minister Pat McFadden he “pushed back” against Mr Streeting’s stance, and criticised him in WhatsApp messages.
September 8 2025
Paedophile financier Jeffrey Epstein’s notorious “birthday book”, full of personalised notes from associates when he turned 50, is released by the US House Oversight Committee.
It includes a message from Lord Mandelson referring to the child sex offender as his “best pal”, heightening scrutiny of the UK Government.
Other WhatsApp messages from May the same year revealed Lord Mandelson had criticised the Department for Business and Trade (DBT) for being “irresponsible” over leaks to the press, and that DBT was later cut out of discussions over a trade deal with the US.
September 10 2025
Starmer says he has “confidence” in the peer and that “due process was followed” as questions mounted over the extent of the former Labour grandee’s links with Epstein.
Downing Street also points reporters to the “extensive vetting” of Lord Mandelson.
September 11 2025
Sir Keir sacks Lord Mandelson after growing pressure to remove him from office, after leaked emails showed the peer sent supportive messages even as Epstein faced jail for sex offences.
The Foreign Office said the emails showed “the depth and extent of Peter Mandelson’s relationship with Jeffrey Epstein is materially different from that known at the time of his appointment”.
September 16 2025
In a joint letter to the Foreign Affairs Committee, Whitehall veteran Sir Olly and Foreign Secretary Yvette Cooper say: “Peter Mandelson’s security vetting was conducted to the usual standard set for developed vetting in line with established Cabinet Office policy.”
November 3 2025
Sir Olly and former cabinet secretary Sir Chris Wormald appear before MPs to answer questions about the appointment process.
Sir Olly tells the Foreign Affairs Committee that “it was clear that the Prime Minister wanted to make this appointment himself”.
Meanwhile, Sir Chris said it was the “normal thing” for security clearance to happen after appointment, but before the person signs a contract and takes up the post.
February 2 2026
Sir Keir urges the disgraced peer to quit the Lords after the publication of a further tranche of the so-called Epstein files, which lead to accusations that Lord Mandelson passed sensitive information to Epstein while he was business secretary in Gordon Brown’s government.
February 3 2026
The Metropolitan Police launch an investigation into allegations of misconduct in a public office after the accusations against Lord Mandelson.
February 4 2026
The Prime Minister tells the Commons Lord Mandelson “lied repeatedly” about the depth of his friendship with Epstein, during the appointment process.
The Commons uses an archaic process called a “humble address” motion to compel the Government to release all files relating to Lord Mandelson’s appointment.
This triggers a behind-the-scenes fact-finding process across the whole of Government, led by Cat Little, the Cabinet Office’s permanent secretary.
February 5 2026
Sir Keir tells reporters that security vetting carried out by the security services “gave him (Lord Mandelson) clearance for the role” amid mounting pressure over the extent of what was known about his links with Epstein.
February 8 2026
Sir Keir’s chief of staff Morgan McSweeney, a long-time ally of Lord Mandelson, leaves No 10.
In his resignation statement, he says: “While I did not oversee the due diligence and vetting process, I believe that process must now be fundamentally overhauled.”
March 11 2026
The first tranche of documents are released in response to the Commons humble address motion.
They reveal senior officials had concerns about the appointment, and that Sir Keir was warned of a “general reputational risk” over Lord Mandelson’s link to Epstein, before announcing him as his choice.
Also in the documents is a note dated November 11 2024, in which then-cabinet secretary Lord Simon Case appeared to advise the Prime Minister to arrange for security clearances to be done “before confirming your choice” for US ambassador if he wanted to make a political appointment.
April 16 2026
The Guardian newspaper reports Lord Mandelson failed the background check by security officials but that Foreign Office officials took the rare step of overruling the decision.
Sir Olly is sacked and the Government says Sir Keir was not aware the former Labour grandee was granted developed vetting against the advice of UK Security Vetting until earlier that week.
April 17 2026
Sir Keir says he is “furious” and that it was “unforgivable” he had not been told that UKSV had advised against clearance.
April 20 2026
In a statement to the Commons, the Prime Minister says a “deliberate decision” was made on “repeated occasions” not to tell him that Lord Mandelson failed to pass vetting, blaming Foreign Office officials for not passing on the information.
He says he would not have proceeded with the appointment if he had known UKSV had declined to approve the peer, and said he “did not mislead the House of Commons”.
April 21 2026
Sir Olly gives his account of the vetting process to the Foreign Affairs Committee, after being sacked.
The former senior civil servant told the committee there was a “dismissive attitude” to vetting by No 10, but Sir Keir later says the mandarin’s evidence “puts to bed” allegations he misled Parliament.
April 28 2026
Morgan McSweeney, the former Downing Street chief of staff, also gives evidence to the Foreign Affairs Committee.
He admits he was “wrong” to advise the Prime Minister to appoint the peer but said he believed Lord Mandelson had been the right choice to deal with Donald Trump’s incoming administration.
Sir Philip Barton, who was the Foreign Office chief before Sir Olly, meanwhile tells the committee Lord Mandelson’s relationship with “toxic, hot potato” Jeffrey Epstein was a known risk to the Prime Minister.
MPs meanwhile vote to reject calls for a parliamentary inquiry over whether Sir Keir misled the Commons about the appointment process.
June 1, 2026
The second tranche of files relating to Lord Mandelson’s appointment are published.
The files are the full scope of what the Government plans to release, apart from documents held back at the request of the Metropolitan Police amid their ongoing investigation into allegations of misconduct in public office.
The documents reveal a host of private discussions between Lord Mandelson and Government ministers, correspondence about business deals, and the peer’s campaigning efforts to secure the chancellorship of Oxford University in 2024.
In one exchange in the files, originally from May 2025, senior minister Pat McFadden criticises the direction of the Government, telling Lord Mandelson: “Every meeting I have is ‘who can we tax in order to pay benefits to others’. They’re asking the wrong questions.”
Elsewhere, it is also revealed that the peer has refused to hand over his private WhatsApp messages for publication.
Darren Jones, the chief secretary to the Prime Minister, tells the Commons the messages could be disclosed through a future court case.
