A mobile phone belonging to Keir Starmer’s former Chief of Staff, Morgan McSweeney, used to communicate with Peter Mandelson, was stolen last year.
The theft has led to fears that information relevant to enquiries into Lord Mandelson’s short-lived appointment as US ambassador in 2024 has been lost.
The New Labour architect was ditched from his prestigious post in Washington in 2025 after close links to the convicted paedophile financier Jeffrey Epstein came to light.
Mr McSweeney’s device is understood to have been reported to the police at the time of the theft, but the messages and data stored on it cannot be recovered.
He served as the Prime Minister's most senior adviser in Downing Street and took "full responsibility" for Mandelson's appointment when he resigned on Febuary 8 over the scandal.
“The decision to appoint Peter Mandelson was wrong. He has damaged our party, our country and trust in politics itself,” he wrote upon his departure.
“When asked, I advised the Prime Minister to make that appointment, and I take full responsibility for that advice.”
Downing Street is now obligated to release all emails, texts, and reports related to the appointment of the New Labour architect to the plum diplomatic post following Parliament's backing of a humble address motion.
Morgan McSweeney's phone, containing messages to Peter Mandelson, was stolen last year
| GETTYThis requirement specifically covers “all electronic communications” between Mr McSweeney and Lord Mandelson.
The mobile was taken months before Parliament passed the arcane mechanism that compelled the documentation relating to the ambassadorial appointment, The Sun reported.
Despite the missing device, some communications between Sir Keir's former top advisor and Lord Mandelson have been located and will be included in the published materials.
Nevertheless, Shadow Cabinet Minister Alex Burghart has raised concerns over last year’s theft of the device.
LATEST DEVELOPMENTS
Downing Street has been compelled to release all emails, texts, and reports related to the appointment of the New Labour architect as US ambassador
|GETTY
"We had to drag the Mandelson files out of Keir Starmer, and now we find the phone of his former Chief of Staff and protege of Mandelson won't be part of the disclosure,” he told The Sun.
"The whole thing stinks of a cover-up."
A Government spokesman stated: "We are committed to complying with the Humble Address in full, while continuing to support the Metropolitan Police with their investigation."
The next batch of the Mandelson Files is scheduled for release next month, following the Easter break.
Lord Mandelson was sacked from the plum diplomatic role last year over his links to Jeffrey Epstein
|GETTY
On March 11, the Government unsealed the first tranche of files, which revealed explosive details of Lord Mandelson's vetting process.
One finding showed that Sir Keir was warned about Lord Mandelson's links to Jeffrey Epstein in December 2024 and cautioned that he posed a "general reputational risk".
The Prime Minister's national security adviser, Jonathan Powell, was also seen as describing the disgraced peer's appointment as UK ambassador to the US as "weirdly rushed" and "unusual".
He was recorded as raising these concerns about the "individual and reputation" to the PM's ex-chief of staff, Morgan McSweeney (MM).
Our Standards: The GB News Editorial Charter