Ministers have been warned not to publish their messages with Peter Mandelson after Wes Streeting released his private WhatsApp exchanges with the disgraced former ambassador.
In a message to officials, the Cabinet Office is understood to have said members of government should not share material that could be covered by a Commons motion forcing the release of documents relating to Mandelson’s appointment as US ambassador.
The Met police are investigating alleged misconduct in a public office following claims that Mandelson passed market sensitive information to Jeffrey Epstein when he was business secretary in Gordon Brown’s government in 2009.
The Met police issued a statement on Tuesday saying it was “vital due process is followed” so as not to jeopardise its investigation.
In an effort to draw a line under his relationship with Mandelson, Streeting published dozens of messages that the pair exchanged between August 2024 and October 2025. In the messages, Streeting said the government lacked a growth strategy and questioned No 10’s communications operation – remarks that appeared to form part of an effort to position himself for a potential leadership contest.
Asked about the issue at an event in Hertfordshire, Keir Starmer said the release of information must be a “managed process” and that his government should be “acting together in this”.
He said: “The issue of text messages and all information that’s being gathered as a result of the humble address last week, that needs to be a managed process, both in government and obviously, there’s a police element to it.”
Asked if he had told off Streeting for releasing his own messages unilaterally, the prime minister added: “I do think that we all need to ensure that we’re all acting together in this, because all the information needs to be pulled together.”
Officers have searched two properties connected to Mandelson as part of the Met police investigation.
In a statement on Tuesday, a Met police spokesperson said: “An investigation into alleged misconduct in public office is under way and it is vital due process is followed so that our criminal investigation and any potential prosecution is not compromised.
“As part of our inquiries, we will review material identified and provided to us by the Cabinet Office to assess whether publication is likely to have a detrimental impact on our investigation or any subsequent prosecution.
“We will work alongside the Cabinet Office to review relevant documents over the weeks ahead. The process to decide which documents should ultimately be published remains a matter for government and parliament.
“As we have stated previously, this investigation may be complex but we are focused on a timely and thorough process so that justice is served in this case, or future ones linked to the Epstein files.”
