Lord Mandelson branded a No10 team “keystone cops” ahead of a crunch White House meeting.
The disgraced peer was also highly critical of Prime Minister Sir Keir Starmer for not seizing the opportunity of the Washington summit for "personal projection".
Thousands of documents and messages related to Lord Mandelson’s appointment and activity as US ambassador were released by the Government on Monday.
One relates to the Prime Minister, French president Emmanuel Macron, German Chancellor Friedrich Merz and other European leaders accompanying Ukraine's leader Volodymyr Zelensky to the White House in August 2025.
They were there to support Mr Zelensky after an angry clash at a showdown with Trump and Vice President JD Vance earlier that year.
Details of preparations for the meeting are laid out in email exchanges between cabinet minister Pat McFadden, when he was Sir Keir's No10 fixer, and Lord Mandelson when he was UK ambassador to Washington.
Lord Mandelson appears to criticise the PM for wanting to “avoid any encounter” with journalists and “avoid all risk”.
He added that “we have a whole lot of No10 keystone cops coming”, a reference to the incompetent policemen featured in silent film slapstick comedies, and said they included Sir Keir's then chief of staff Morgan McSweeney.
Mandelson branded No10 team travelling to White House 'keystone cops'
[17/08/2025, 16:03:48] Pat McFadden: Yes of course. I see Keir will now be at WH meeting with Z (Zelensky).
[17/08/2025, 16:06:16] Peter Mandelson : Yes. Morgan is coming with him. The media prep is interesting. Completely reductionist for Keir. Want to avoid any encounter with journos that might involve him answering a question. No sense of opportunity for personal projection. Just avoid all risk. Always the same.
17/08/2025, 17:35:25] Pat McFadden: I spoke to him. It's a bit of a whirlwind. This external strategy unit idea has come from a lack of belief that good people will come in to number 10 and it's hard to get the bad ones to leave.
[17/08/2025, 17:35:41] Pat McFadden: I'm going to see him when he comes back.
[17/08/2025, 17:40:26] Peter Mandelson : I told him he needs an instrument/entity to recruit top people but I fear he is using excuse to keep people because he knows Keir won’t fire them.
[18/08/2025, 13:07:11] Pat McFadden: Let me know how it goes?
[18/08/2025, 14:12:09] Peter Mandelson : We have a whole lot of No10 keystone cops coming, including Morgan, falling over themselves and complaining they won’t all be in the Oval (none of us will be).
The latest release of files related to Lord Mandelson includes a number of WhatsApp messages exchanged with a series of government ministers.
The files also reveal Lord Mandelson “declined to comply” with a request to hand over his WhatsApp messages and other information on his personal phone to the Government.
But information has been shared by a number of MPs and ministers.
On July 20, 2025 he told pensions minister Torsten Bell “the government doesn’t do policy, generally speaking, well enough”.
Mr Bell told him: “That is definitely true – everyone seems to think it’s someone else’s job to get the policy right … Which is very odd.”
Lord Mandelson replied: “As the saying goes, rubbish in rubbish out…”
A handwritten note from Lord Mandelson to then-foreign secretary David Lammy said the Government would “never regret” appointing him as ambassador to Washington DC.
The letter, written in blue pen on notepaper headed with Lord Mandelson’s name and a House of Lords seal, and dated November 18, 2024, read: “Dear David, As today (and all week) is polling day in Oxford and I am returning to London, I wanted to drop you a line, personally, about Washington.
“Thankfully, the media speculation has gone away and I hope this was not too irritating to you. I just wanted you to know that if you were minded to appoint me I would make sure you never regret it.
“I fear that navigating Britain’s interests through the Trump administration will require super-human skills and luck and a massive team effort.
“There is so much riding on it, on security and defence, on trade and economy and on the relationship, not to mention China.
“If we all put our best minds and energy to it, I think we can pull it off but we have to be realistic.
“For me it would be the last thing I do in public life and it would be a huge honour to serve you and the Government in this role. So if you are up for it, so am I.”
Some messages between ministers and Lord Peter Mandelson “may not have been backed up” because of disappearing messages or a change in devices, Chief Secretary to the Prime Minister Darren Jones admitted on Monday.
Mr Jones said this included some of his own messages with the disgraced peer.
He told the Commons: “I can confirm that we have conducted multiple rounds of discovery from relevant ministers, special advisers and officials in line with the motion passed by the House. This has involved requesting searches of email messaging platforms, such as WhatsApp and other related communication services on both work and personal devices.
“However, the House should note that some messages may not have been backed up where devices may have been changed or disappearing messages were turned on for reasonable and permitted reasons, including before the dismissal of Peter Mandelson, or the passing of the humble address, myself included.”
The files released about the appointment of Lord Peter Mandelson as US ambassador detail a “failure that is visible from space”, the Conservatives have said.
Tory shadow Cabinet Office minister Alex Burghart said Sir Keir will always be remembered for the failure as he urged more details of what was not able to be published. He also said he and others were not given enough time to scrutinise the papers before the statement.
Replying to Mr Jones in the House of Commons, Mr Burghart said: “It was (the Prime Minister’s) error. It was clear that due diligence was not followed.
“It is a failure that is visible from space, it is a failure that will define this Prime Minister’s premiership, it is a failure that will be written as his political epitaph.”
