UK envoy to Japan may testify in Mandelson security clearance probe

The UK’s next ambassador to Japan could be called to give evidence over a decision to award Peter Mandelson security clearance against the advice of vetting officials, a parliamentary committee is considering.

Corin Robertson, the Foreign Office’s chief operating officer at the time, was involved in the late January 2025 decision to grant Mandelson clearance, according to evidence given to MPs.

Robertson, set to take up her Tokyo post in August, is the only one of three senior civil servants involved who has not yet been questioned by parliament.

A source on the foreign affairs select committee, which is investigating Mandelson’s appointment as ambassador to the US, said it would consider this week whether to call Robertson to give evidence, either verbally or in writing.

The committee is nearing the end of its investigation but is expected to wait for the release of further documents under the so-called humble address system before reaching final conclusions.

The decision to grant Mandelson clearance was made by Olly Robbins, the FCDO’s most senior civil servant. Robbins was sacked by Keir Starmer three weeks ago after the Guardian revealed he had granted clearance despite the vetting agency recommending denial.

Starmer said Robbins’s failure to inform him was “unforgivable” and he was “furious” about what happened. Robbins has insisted he was right not to divulge information from the vetting process to ministers.

Robbins gave evidence last month. The FCDO’s former head of security, Ian Collard, also involved, did not appear but responded via a letter from the Foreign Office.

Robbins and Collard said they had not read Mandelson’s vetting summary from United Kingdom Security Vetting (UKSV), relying instead on verbal briefings. Collard’s evidence highlighted Robertson’s role.

Her appearance could help resolve unanswered questions, as MPs struggle to piece together events hampered by a lack of written records or audit trails of the Foreign Office’s decision-making on Mandelson’s vetting.

Robbins and Collard relied on recollections of conversations and briefings that appear not to have been minuted. Robertson could be asked to corroborate these discussions.

It is now understood UKSV advised Collard’s department on 29 January that there was “high” concern about Mandelson and security clearance should be “denied”.

However, Starmer had already confirmed Mandelson as his pick for ambassador, with Robbins testifying there was “pressure” to get him to Washington.

Collard said he initially spoke about Mandelson’s vetting with Robertson, only talking to Robbins after he briefed her.

Collard told MPs, in evidence submitted on his behalf by the FCDO, that Robertson agreed “the risks could be mitigated” and Collard should take Mandelson’s case to Robbins for a “final decision”.

It is unclear whether Robertson reviewed the contents of Mandelson’s vetting file or relied on an oral briefing based on notes taken by Collard, who had in turn been orally briefed.

The Cabinet Office permanent secretary, Cat Little, testified that “anyone within the security chain” could request to see vetting information “if they feel it is necessary.”

Robbins and Collard also claimed UKSV had described Mandelson’s case as “borderline,” although no publicly released evidence confirms this, and no other official who saw the file has described it that way. If called, Robertson could face questions about whether she recalls being told the case was “borderline” and what evidence supported that.

After Robbins’s decision to grant clearance, Collard sent an email to Robertson and one of Robbins’s close aides.

According to evidence heard by MPs, the email noted Robbins’s decision and mitigations but did not set out the risks identified by UKSV. It has been provided to the Cabinet Office, which is collating documents for public release under the humble address motion requiring disclosure of “all papers” relating to Mandelson’s appointment.

Robertson may be called to explain why Robbins and Collard sought to access copies of Mandelson’s vetting file in September 2025, after Mandelson was withdrawn from office. Neither has given an explanation for why they requested the file at that stage, despite not reviewing it seven months earlier when granting clearance.

Robertson, via the FCDO, did not respond to requests for comment.

The latest tranche of documents released under the humble address is due to be published by the government in the coming weeks, but there are growing concerns the files will be incomplete or censored.

On Friday, the intelligence and security committee, a parliamentary group reviewing the most sensitive Mandelson documents before release, criticized the government for withholding his vetting file and applying redactions “far too broadly.”