LONDON — Prime Minister Keir Starmer’s carefully built relationship with Donald Trump could be torpedoed by the disclosure of Peter Mandelson’s communications as ambassador, U.K. officials fear.

Starmer will have to publish documents relating to the ex-Labour peer’s appointment as ambassador after demands from MPs across the political spectrum for greater transparency about the process. While it is not yet known exactly what will be published, the files may include messages from Mandelson to officials at No.10 Downing Street and the Foreign Commonwealth and Development Office. 

Two senior Whitehall officials, granted anonymity because they were not authorized to speak on the record, told POLITICO they are concerned about what the former envoy — known for his ruthlessness and candor — may have said about Trump to his colleagues, and how they responded to him.

One of the officials said there is “lots which could be damaging” and “he [Mandelson] used to download his thoughts in real time.”

They point out that parliament’s Intelligence and Security Committee, which will sift through the documents before publication, will only be looking for matters that could jeopardize national security, rather than cause embarrassment or rifts.

In a further sign of the shockwaves going through the diplomatic establishment, FCDO permanent secretary Oliver Robbins wrote to all departmental staff Wednesday night to reassure them over the “anxiety” caused by the whole affair.

He asked civil servants approached about communications that may be disclosed to refer all requests to his office.

In the message, obtained by POLITICO, Robbins said, referencing the PM’s earlier expression of regret for appointing Mandelson: “I am also sorry about this episode, which I know will have affected staff particularly in our U.S. team but also across the workforce.

“I want to acknowledge that anxiety and reassure you that my recommendations as head of the diplomatic service to the foreign secretary for the many roles in our department carrying enormous trust and leadership responsibility are guided by my deep concern to preserve and enhance our service’s reputation for merit, professionalism and integrity.”

National security exceptions

The ISC has specified that papers which are national security related should be sent to them unredacted, and the government should provide an explanation as to exactly why pieces of information are prejudicial.

“We believe the motion is clear that those papers which the government is required to provide to the ISC must be disclosed, unredacted, to the ISC,” the committee said in a letter to the PM and cabinet secretary. “The government may not decline to disclose any in scope material altogether”

Kevan Jones, chair of the committee, told the BBC that the panel would put “as much as possible in the public domain.”

One of Mandelson’s predecessors as ambassador, Kim Darroch, was forced to resign in 2019 over his criticism of Trump’s “dysfunctional” administration, made in confidential diplomatic cables that were made public. 

But both senior officials cited above made it clear that Mandelson may not have always used cables for his musings on Trump, instead often using email and texts.

Mandelson, one of the architects of New Labour who helped bring Tony Blair to power in 1997, returned to high office last year when he was named as the British ambassador to Washington despite his known links to the pedophile Jeffrey Epstein. 

He was forced out of that role in September after it was reported he had continued a closer relationship with Epstein after the late financier’s conviction than was previously publicly known. 

Mandelson did not immediately respond to a request for comment. He has not commented on the police investigation, but has previously said he was wrong to have continued his association with Epstein and apologized “unequivocally” to Epstein’s victims.

The scandal was reopened Monday when emails released as part of the Epstein files appeared to show Mandelson leaking internal government discussions in the wake of the 2008 financial crash. 

Police are now investigating allegations of misconduct in public office against him, which they have warned may limit some of the information which is made available.