Peter Mandelson scandal: the key questions that remain unanswered | Peter Mandelson

The parliamentary inquiry into the appointment of Peter Mandelson as US ambassador heard more than 77,000 words of evidence from five of the most senior officials and advisers in the government. But as MPs on the foreign affairs select committee meet this week to discuss next steps, there are concerns that important questions remain unanswered.

The committee’s investigation was hampered by a lack of documentary evidence, amid concerns that the government had failed to comply with the terms of a parliamentary motion ordering the release of “all documents” relating to the appointment.

A source on the committee said MPs planned to meet on Tuesday, with options ranging from drawing preliminary conclusions to expanding the investigation to demand further responses from the State Department.

Their debate comes at a pivotal moment for Keir Starmer. The decision to appoint Mandelson in December 2024 cast a shadow over his tenure as prime minister and led to repeated calls for his resignation. One of his potential rivals for the Labor leadership, Wes Streeting, who resigned as health secretary last week, also faces questions over his closeness to Mandelson. Streeting has previously said he was never a close friend of Mandelson.

There are concerns that any conclusions the committee reaches at this stage may be premature. The release of the next part of the files on Mandelson, as part of a parliamentary motion known as a modest speech, is not expected until June.

And there are a number of unanswered questions, particularly in relation to the evidence given by Olly Robbins, the former permanent secretary of the Foreign Office who gave Mandelson the go-ahead and was later sacked by Starmer.

oral briefings

So far, the committee has focused on a decision Robbins made within a few hours in late January 2025.

Starmer had announced weeks ago that he would choose Mandelson for the top diplomatic post, and Robbins and others have said there was pressure from Downing Street to send the ambassador-designate to Washington. Mandelson’s vetting was assumed to be a formality.

Like nearly everyone in the State Department, even junior civil servants, Mandelson needed an “enhanced review” security clearance. The risk assessment was carried out by the UK Security Review (UKSV), an agency within the Cabinet Office, but the final decision was left to the Foreign Office.

UKSV officials completed their assessment on January 28, after interviewing Mandelson twice and reviewing his background. A document summarizing the agency’s findings and conclusions reached the Ministry of Foreign Affairs via the “secure portal” at 13.52 the next day.

UKSV assessed Mandelson as being of “high” concern overall and said the recommended clearance should be refused. But within a few hours, the State Department decided to allow Mandelson, despite this advice, with mitigating measures.

A source at the foreign affairs select committee said a lack of transparency around Mandelson’s review prevented MPs from questioning the accuracy of Robbins’ decision. Committee members were not told why UKSV considered Mandelson a national security risk or what mitigating measures were put in place.

It’s unclear whether the next batch of documents released by the humble address will contain the answers. On Friday, the intelligence and security committee, a parliamentary group of MPs and colleagues who review the most sensitive Mandelson documents before they are released as part of the modest address process, criticized the government for withholding Mandelson’s review dossier and applying redactions “too broadly”.

Robbins, the most senior civil servant in the State Department as permanent secretary, was ultimately responsible for granting Mandelson leave. Robbins defended that decision in his statement, but admitted to MPs that he had not read the UKSV document summarizing Mandelson’s review dossier.

Robbins said he relied on a verbal briefing about its contents from security chief Ian Collard, a career diplomat, rather than asking to see the document, which was said to be about 10 pages long.

Collard did not give evidence, but a letter sent to the committee on his behalf by the Secretary of State revealed that he, too, had not read the UKSV summary document. Instead, he relied on a verbal briefing from an unnamed official on his team.

The State Department’s letter revealed the involvement of a third official: the department’s then-chief operating officer, Corin Robertson. It was stated that Collard discussed UKSV’s findings with Robertson, who agreed that “the risks could be reduced” and said Collard should take Mandelson’s case to Robbins for a “final decision”.

The committee is now considering whether to invite Robertson, who will become Britain’s ambassador to Japan in August, to give evidence.

When asked why he did not display the short UKSV summary document, Robbins said such files were extremely sensitive and should remain in a “hermetically sealed box”.

Robbins said it would take a “completely exceptional situation” for him to review such a file. Committee chairwoman Emily Thornberry asked Robbins: “This is a completely exceptional situation, isn’t it?” He replied: “No.”

The Guardian understands that the document was marked “official – sensitive”, a routine classification for government documents, and does not qualify as “secret” or “top secret” files, where access is highly restricted.

Giving evidence to the same committee, Cabinet Office permanent secretary Cat Little said “anyone in the security chain” could request such information if they felt it was necessary.

‘Borderline’ confusion

Another point of confusion arising from Robbins’ statement was his widely reported claim that Mandelson’s case was less than straightforward.

Robbins told the committee he had been told that UKSV “viewed Mandelson as a borderline case” and was “leaning” towards simply refusing permission.

Committee members were stunned by this claim. The Agency’s conclusions were marked with two red boxes in the summary file; signs indicated that Mandelson was of “high” general concern, leading to a “permission refused” recommendation.

A template of the document published by the Cabinet Office suggests UKSV had the option of a “yellow” permit approved with “risk management” but chose the more serious option “permission denied”.

MPs on the committee, who were reportedly briefed on the summary document by the Cabinet Office, questioned Robbins repeatedly on this point.

No documents supporting the “borderline” claim have been released since his statement. And no witness who testified at trial, other than Collard, used that word.

Starmer, who has seen the summary document, made no reference to the case being “borderline” when briefing the House of Commons on UKSV’s findings. Little, who saw the document, also did not see it when he testified to the committee.

post dismissal

Although Robbins was firm in his statement that it would be wrong for him to review Mandelson’s review file summary when granting him permission, he told MPs he wanted to see the file in seven months.

Mandelson withdrew from the Washington embassy on September 11, 2025, after her relationship with sex offender Jeffrey Epstein was revealed.

According to Robbins, around this time he was asked questions about whether he could see the document. He told MPs he didn’t think the Cabinet Office needed to see it because it needed a national security justification for it.

Collard also asked to see the summary document around this time. No officials have yet been asked to explain why they wanted to see the UKSV document after Mandelson lost his job.

According to Little, the document was emailed to Collard’s team four days after Mandelson’s dismissal.

What happened next is one of the most important mysteries the committee can now try to solve. The State Department said the security chief took notes as a “souvenir note” when Collard reviewed the document in mid-September 2025.

It ticked the boxes “high concern” and “permission denied.” But the letter added: “It also noted that UKSV’s recent case assessment had ticked the boxes as well as stating: ‘Overall I believe this is a very borderline case.”

The Committee may now request clarification of this sentence. When Collard referred to an “extremely borderline case”, was he referring to official UKSV documents that he had viewed for the first time? If so, why did no other official or minister refer to such a UKSV document when briefing parliament?

Alternatively, could Collard have produced a recording of something he claims was said seven months earlier in September 2025? So who exactly told Collard that the case was “very borderline” and when?

The Guardian put these questions to the Foreign Office and Robbins. Neither of them gave any answer.