Potentially explosive evidence about Peter Mandelson’s alleged efforts to influence a Cabinet reshuffle to secure more political influence for his allies has been kept out of the public eye.
Messages between the disgraced former ambassador to the US and Sir Keir Starmer’s one-time chief of staff Morgan McSweeney were expected to be released as part of a second tranche of documents made public last week.
But their absence has sparked mystery in Whitehall, with suggestions they were being held back as the police probe into Mandleson’s alleged misconduct in public office widens its scope. However, that was dismissed by a Met source last night.
The messages are understood to show that while in his Washington job, the Labour grandee lobbied for Peter Kyle to be made business secretary – a role he was duly given in last September’s shake-up.
In his previous job as science and technology secretary, Mr Kyle had been a cheerleader for the artificial intelligence sector that had been a lucrative source of income for Lord Mandelson’s consultancy business.
Messages show he publicly spoke out in support of the controversial technology after Mandelson suggested he should.
One minister told The Mail on Sunday last night: ‘Peter thought it was impossible to properly promote the AI agenda unless Kyle was business secretary.’
In one message, Mandelson is thought to have said to Mr McSweeney: ‘Are you taking Peter away from me?’
Peter Mandelson, pictured here at the Milken Institute Asia Summit in Singapore in September 2019, is said to have lobbied for Peter Kyle to be made business secretary – a role he was duly given in last September’s shake-up
Business Secretary Peter Kyle arrives outside Downing Street before a Cabinet meeting in May
A senior Government source last night told the MoS that the reshuffle messages had not been published because police ‘have held [them] back’ so as not to prejudice the ongoing criminal investigation into the peer’s communications with paedophile financier Jeffrey Epstein when Mandelson was in Gordon Brown’s government.
However, a senior source involved in the investigation told the MoS the messages were not currently part of the probe and had not been held back at their request. But they did say the messages might be ‘reviewed’ later.
Mandelson co-founded an advisory firm called Global Counsel which had commercial dealings with AI giants OpenAI and Palantir.
In February 2025 – two days before Mandelson took up his role as US ambassador – the peer told Mr Kyle that his keynote speech to the Munich Security Conference would ‘benefit from more positive language about AI upfront’. Mr Kyle responded: ‘That’s all v good advice which I’ll action.’
Six days later, Mr Kyle used his address to welcome a ‘new era of wealth and prosperity’ aided by the technology.
By that point, Mandelson had stepped down as a director of Global Counsel, but still retained a large shareholding.
A Cabinet Minister told the MoS: ‘Peter had been working closely with Kyle. He had been lobbying for him to [be] business secretary.’
The withheld messages from Mandelson to Mr McSweeney are understood to include the line: ‘Have you solved the Darren problem?’, relating to Darren Jones, chief secretary to the Treasury at the time. He was made chief secretary to the PM in the reshuffle.
Morgan McSweeney, the former chief of staff to Keir Starmer, speaks at an event in Prague, Czech Republic, in May
Mr Jones was revealed last week to have contacted Mandelson when he was sacked over his Epstein links with the fawning words: ‘You’ve been doing such a great job, and you worked wonders with Trump. I’m so sorry about today.’ The disclosure came after Mr Jones had denied sending such a message.
Last week’s tranche of messages also showed Mandelson apparently lobbied on behalf of Jon Garvie, a former colleague at Global Counsel who is now strategy director of the government’s National Security Secretariat.
Mr McSweeney told MPs this year that Mandelson had not influenced the reshuffle, insisting: ‘I did not respond to any of Mandelson’s texts. None of his suggestions actually came out to be the case, so his ideas were not followed up.’
However a Cabinet source said: ‘[Mandelson] was directly involved. The messages show the people he was expressing an interest in were the same people who did actually get moved’.
No 10 declined to comment last night. The Met has said its inquiry is ongoing and has requested that any material is not published until it has had the opportunity to review it.
Mandelson strongly denies claims of misconduct in public office or that he was motivated by financial gain.
