Keir Starmer's former chief of staff Morgan McSweeney has been asked to hand over text messages concerning Peter Mandelson from his personal mobile phone.
The cabinet office is continuing its investigation into Mandelson's selection as US ambassador in December 2024 and members have requested McSweeney to share 'relevant' text messages.
The move could lead to the publication of text messages McSweeney had with Lord Mandelson and others concerning his appointment, The Telegraph reports.
Lord Mandelson himself has been asked to supply messages from his personal phone as part of his disclosure of files
It comes as the Met Police stated it is reopening its investigation into the reported theft of Mr McSweeney's Downing Street phone, which his political opponents allege has been concocted to prevent disclosing sensitive messages.
MPs moved in February to force the publication of tens of thousands of documents amid questions over how much was known about Lord Mandelson’s links to Jeffrey Epstein before the peer was handed the Washington job.
The Cabinet Office is working on an information-gathering plan and will ask the ex-Labour grandee to provide everything he holds in scope of the humble address used to compel the release of correspondence, according to Government sources.
They say this will include requesting data from his personal phone and stressed this had already been part of the plan.
The Times reported that the Cabinet Office had not asked Lord Mandelson for any messages on his personal device and instead were attempting to piece together correspondence by asking ministers and officials to provide it from their side.
Lord Mandelson, a political appointment rather than a career diplomat, was sacked from his Washington role in September last year over his links with Epstein, who died in 2019.
The first tranche of documents related to the decision was published earlier this month after a demand for transparency by MPs, with more to follow.
Since it emerged that the phone of the Prime Minister’s then-top aide was stolen in October 2025 and not backed up, concerns have been raised about it leading to the loss of the correspondence.
The Prime Minister called it “far-fetched” to suggest the theft was linked to the release of files on Lord Mandelson.
