Why the British prime minister is fighting to keep his job

The United Kingdom has seen remarkable churn at the highest level of government, going through six prime ministers in the last 10 years, largely due to turmoil within the Conservative Party.

Now Keir Starmer, the leader of the Labour Party and U.K. prime minister since 2024, could be headed for the exits as well, thanks to a storm of scandal, procedure, and politics.

What is the controversy?

The root of the issue is the appointment of Peter Mandelson, a longtime Labour Party politician, as British ambassador to the United States in February 2025. Mr. Mandelson has had a history of controversy in his career, having twice resigned from government Cabinet positions over conflict-of-interest concerns.

The problem for Mr. Starmer is that when Mr. Mandelson was publicly tabbed for the U.S. ambassadorship, he was then subject to vetting by the U.K. Security Vetting office to grant him security clearance. The vetting turned up multiple concerns surrounding Mr. Mandelson, including his known past controversies, as well as his personal relationship with the late financier and convicted sexual abuser Jeffrey Epstein. As a result, the office ruled Mr. Mandelson a security risk and denied him clearance.

Nonetheless, Olly Robbins, the then-permanent secretary of the Foreign and Commonwealth Office, decided to overrule the UKSV’s decision and granted Mr. Mandelson security clearance. Mr. Mandelson went on to serve as ambassador from February 2025 to September 2025, when he was removed from office after details about his connections to Mr. Epstein over many years came to light.

Chris J Ratcliffe/Reuters

Former British ambassador to the U.S. Peter Mandelson walks his dog, as he returns to his residence in London on April 17, 2026.

Though he was never accused of sexual misconduct himself, Mr. Mandelson later came under investigation for passing along sensitive government information to Mr. Epstein – further highlighting the failure of his earlier vetting.

Mr. Robbins was fired by the prime minister on April 16, after a report in The Guardian revealed that a decision to deny Mr. Mandelson a security clearance was overruled by the Foreign Office.

Why is the controversy threatening to bring down the prime minister?

The most immediate reason is that it looks like he might have lied to Parliament.

While Britons are just as wont as any other citizens to complain about their politicians being dishonest, members of Parliament are forbidden from directly lying or knowingly misleading the House of Commons, under parliamentary procedure. This is especially true for prime ministers, who, if caught lying, are expected by tradition to resign their post.

That’s one of the big questions currently surrounding Mr. Starmer. Earlier this year, the prime minister said that Mr. Mandelson passed vetting, which could be interpreted as a lie. In a February press conference, he said that “security vetting, carried out independently by the security services, ... gave [Mr. Mandelson] clearance for the role.” The prime minister has said he was not told of a decision to deny clearance until later, and blames the situation on a failure of process, which he has promised to address.

Mr. Robbins, the former permanent secretary of the Foreign Office, muddied the water on Tuesday. In testimony given to a parliamentary committee, he said he did not tell Mr. Starmer that Mr. Mandelson failed his UKSV vetting. But he did say that his office was “under constant pressure” from the prime minister’s office at No. 10 Downing St. to get Mr. Mandelson approved, and that the Cabinet Office – the ministerial department that supports Mr. Starmer – believed “there was no need to vet Mandelson.”

What else is driving the scrutiny of Mr. Starmer?

The deeper issue that is dogging the prime minster is simply that he is deeply unpopular right now.

The results of tracking polls released by YouGov on April 20 show 70% of respondents saying that Mr. Starmer is doing his job badly, with only 22% thinking he’s doing his job well. Those figures have been holding roughly steady since last August.

That’s a real problem for the Labour Party, which is facing the possibility of an electoral disaster in upcoming local elections on May 7. Though the elections are primarily to local councils and regional parliaments in Wales and Scotland, polling shows Labour at risk of major losses in once-impregnable areas to upstarts the Green Party and Reform UK. Of particular concern are the London boroughs, where a new YouGov poll predicts Labour will lose control of half of the 12 councils where it currently holds a majority.

With so much at stake politically, many Labour politicians are thinking that replacing Mr. Starmer may be the politically expedient thing to do. Whether that happens before the May 7 elections is still uncertain. But if Labour gets blown out as badly as expected – or worse – he may become the scapegoat, whatever the determination around Mr. Mandelson’s vetting.