Starmer on the brink after revelation Mandelson failed security vetting before becoming US Ambassador

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The disgraced peer was initially denied clearance in late January 2025 after a highly confidential background check by security officials, multiple sources say.

A few weeks later, Sir Keir Starmer announced Mandelson as the UK’s chief diplomat in Washington.

Following the revelation, the Foreign Office is “working urgently” to comply with a request by the Prime Minister to establish the facts around how vetting was granted for Mandelson to become ambassador to the US, an FCDO spokesperson said.

Reform UK and the Green Party have called for Starmer to resign, while the SNP have reported him to the ethics advisor.

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Foreign Office officials allegedly used their authority to override the recommendation from security officials to ensure the appointment could go ahead.

No.10 has since revealed that Starmer was not aware the Foreign Office had overruled the vetting decision until earlier this week.

Mandelson’s failure to secure vetting approval was revealed by The Guardian, following calls for the government to disclose the details amid intense scrutiny over his appointment.

So far, Downing Street has released 147 pages of documents in an attempt to shed light on the case.

Further documents are set to be released, but senior government officials are said to be deciding whether to withhold documents about Mandelson failing the vetting process from Parliament.

The decision, which rests with the Cabinet Office, has not yet been taken.

Withholding documents from the Intelligence and Security Committee could amount to a breach of a parliamentary motion to release “all papers relating to Mandelson’s appointment”.

The revelation about Mandelson not being granted clearance by UK Security Vetting (UKSV) will raise further questions about why the Prime Minister appointed him.

UKSV is a division of the Cabinet Office that scrutinises the background of prospective civil servants and conveys its decision as a recommendation to government departments.

Their vetting decisions are almost always enforced by government departments, but they technically have the authority to override the recommendations.

The reason that UKSV recommended that Mandelson should not receive clearance will be subject to intense speculation.

As part of their vetting process, individuals have to fill out a questionnaire and interviews requiring disclosure of highly private information, including about personal finances, business connections and sexual history.

It is understood that outright denial, as seen in the Mandelson case, is rare.

But what is more exceptional is for the decision to be overruled by a government department. A decision which is said to have taken place over 48 hours in late January 2025.

Starmer will also face accusations that he misled the public in remarks about the security vetting process, which he said had given Mandelson "clearance for the role".

Sir Olly Robbins, the current permanent secretary in the Foreign Office, was the department’s top civil servant in late January 2025 when the decision was made.

Robbins was a few weeks into the role at the time of the decision and was Mandelson’s soon-to-be line manager, which suggests he would have been involved in the decision.

David Lammy, who is now the deputy prime minister, was the foreign secretary at the time.

A decision of that magnitude may also have warranted political approval, or at least consultation, which would have involved Mr Lammy.

Sir Keir's then chief of staff, Morgan McSweeney, could also now be asked whether he had any involvement in, or knowledge or, the decision to overrule UKSV’s denial of clearance.

Mr McSweeney resigned in February over his role in appointing Mandelson, and his friends say he did not know the US ambassador's vetting process or the outcome.

Seven months after Mandelson was appointed US ambassador, he was sacked over his relationship with the convicted sex offender Jeffrey Epstein.

LBC understands Mandelson was not aware that he had allegedly failed vetting, and the matter is not believed to have been raised to him.

A government spokesperson said: "The security vetting process for Peter Mandelson was sponsored by the FCDO. The decision to grant Developed Vetting to Peter Mandelson against the recommendation of UK Security Vetting was taken by officials in the FCDO.

"Neither the Prime Minister, nor any Government Minister, was aware that Peter Mandelson was granted Developed Vetting against the advice of UK Security Vetting until earlier this week.

"Once the Prime Minister was informed he immediately instructed officials to establish the facts about why the Developed Vetting was granted, in order to enact plans to update the House of Commons.

"The Government is committed to complying with the Humble Address in full as soon as possible. Any documentation within the scope of the Humble Address that requires redaction on the basis of national security or international relations will be provided to the ISC. This will include documents provided to the FCDO by UK Security Vetting."

Diane Abbott MP, the Mother of the House, told LBC's Tonight with Andrew Marr that she didn't believe that Sir Keir did not know about Mandelson's failed vetting.

The MP for Hackney North and Stoke Newington told Andrew: "I never bought the story that Keir Starmer wasn't told in the first place. When I came down from Cambridge, my first job was as a career civil servant, and you get the most elaborate vetting in the civil service, even if you're new, like myself.

"So the idea that he's now still saying he didn't know. This is a man who was the Director of Public Prosecutions. The fact that he wasn't across these matters is just not credible."

When asked about whether the Prime Minister should resign over the scandal, Ms Abbott said: "Well, I think he needs to consider his position.

"You cannot mislead the House in this way. You just can't. Everybody knows that. So I think he has to consider his position

"He made a lot of his reputation by finally enabling Boris Johnson to go. And the accusation then was that Boris Johnson had misled the House and that we were going to get a completely different atmosphere now, a completely fresh page would be turned. It doesn't feel that way today..."

SNP’s Westminster Leader, Stephen Flynn, has written to the Independent Adviser on Ministerial Standards, Sir Laurie Magnus, to request an investigation into evidence Starmer lied to the public over the Mandelson scandal.

In a social media post, the Green Party called for the PM to resign.

"Peter Mandelson failed his Government security vetting.

"Starmer appointed him as ambassador to the US anyway.

"No more buck passing, no more mysteriously vanishing mobile phones, we need the truth. Starmer must go."

Reform have also called for him to quit.