Sir Keir Starmer faces a showdown in the Commons on Monday afternoon after it was revealed last week that Peter Mandelson failed crucial security vetting for his appointment as US ambassador, but was given the role anyway after Foreign Office intervention.
The prime minister had already announced that Lord Mandelson would be sent to Washington when he was denied critical clearance, but the Foreign Office took the rare step of overruling the recommendation, the government has admitted.
The prime minister has been accused of misleading parliament over the appointment, prompting calls for him to resign.
Number 10 has insisted he did not know about the failed vetting until last week – despite The Independent revealing in September concerns Lord Mandelson had failed MI6 checks, over worries about his business links to China and fears that his past links to Epstein “would compromise him”.
The government has admitted officials in the Foreign Office overruled the recommendation, but Downing Street claims top Foreign Office civil servant Olly Robbins failed to raise security concerns with officials, prompting him to be sacked.
That is despite The Independent putting those same concerns to No 10 the same day Lord Mandelson was sacked over his links to Jeffrey Epstein on 11 September.

A government spokesperson said: “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.”
Why did Lord Mandelson fail vetting?
Developed vetting is used by the Foreign Office for the highest-level individuals and subjects them to very deep scrutiny. Applicants must go through a thorough process that includes a questionnaire, character references, financial history checks and an in-depth interview with a vetting officer.
This interview can be “intrusive and some individuals may find themselves distressed or triggered”, official government guidance states. It can last for several hours and span topics including sexual history, internet usage and lifestyle and beliefs.
Rather than a simple pass or fail, some individuals can be awarded clearance with caveats, but most applicants pass.
The veteran politician’s relationship with Epstein was likely flagged during the process, although the depth of his connection with the late financier may not have been clear, given that his appointment was prior to the release of the extensive Epstein files.

Email exchanges between the pair, lasting decades, appear to show a lengthy, wide-ranging and intimate relationship including, most notably, when Lord Mandelson served as business secretary in Gordon Brown’s Labour government.
Messages suggest the former minister may have shared internal cabinet business with Epstein, giving him key updates before they were announced. He was later arrested on suspicion of misconduct in public office in February and remains under police investigation.
Through his various business interests, Lord Mandelson has also had links to both Russia and China. Upon assuming the role of US ambassador, he was required to step back from his role at the consultancy company Global Counsel, which he co-founded, whose clients included Chinese brands Shein and TikTok.
Security officials at the Cabinet Office previously raised concerns about the peer’s former role as a non-executive director at Sistema, which is a shareholder of the defence company RTI. A report pointed out that RTI produced technology “for Russia’s land-based missile early-warning system,” and described Sistema’s chairman as a “Putin ally”.
There are several reasons a person could fail vetting. These included dishonesty during the process, or issues that arise that may call into question their suitability for the role. No 10 has not disclosed why Lord Mandelson failed the process and has not indicated any intention to do so.
Further documents on the former Labour peer’s appointment are set to be released in the coming months as part of a parliamentary inquiry into the scandal.
Starmer-Mandelson latest: PM told to wait for vetting before appointing US ambassador
Labour’s youth unemployment tsar hits out at ‘exam-obsessed’ British schools
Starmer faces Commons showdown over Mandelson vetting scandal
UK Government ‘asleep at the wheel’ over Mandelson, says Swinney
How to register to vote in local elections with deadline hours away