Standing outside 10 Downing St the next day, Starmer pledged to restore “respect to politics” and lead a government of “public service”. After the chaos of the last years of Conservative rule, which saw a constant churn of scandal and the toppling of prime ministers Boris Johnson and Liz Truss in quick succession, Starmer promised to lower the temperature and make politics a little bit more boring.

Some of the problems that felled him were baked into his victory, which was built on a wide but shallow base of support. Despite Labour's huge majority in Parliament, it was backed by only 34% of voters — and many of those appeared motivated by anger at the Conservatives rather than enthusiasm for Labour.

This lack of excitement for his government from the start was compounded as Starmer made a series of missteps.

An early furore over accepting free gifts including designer spectacles and Taylor Swift concert tickets, was followed by a series of policy U-turns, especially clumsy attempts to cut welfare spending that stirred anger in Labour ranks.

What ultimately cost him his job was appointing Peter Mandelson to the plum post of the UK's ambassador to the US.

Mandelson was seen as someone who could help Britain navigate US President Donald Trump's second term. His trade expertise and comfort around the ultra-rich were considered major assets. He helped secure a trade deal that spared Britain some of the tariffs Trump has imposed on countries around the world.

But the choice of Mandelson — who in 2003 called himself Epstein's “best pal” — backfired spectacularly when documents came to light in September 2025 showing how close his ties to Epstein had been. Starmer fired Mandelson, but further revelations in the following months plunged his leadership into crisis.

Because Starmer entered politics in his 50s, after a successful law career, he lacked the “political radar” to spot potential booby traps, Ford said.

Starmer's legal career culminated in him becoming chief prosecutor for England and Wales, a role that included prosecuting people charged with terrorism, organised crime and other serious offences.

He was knighted for his role leading the Crown Prosecution Service, and opponents liked to use his title, Sir Keir Starmer, to paint him as elite and an out of touch “lefty London lawyer”.

That view of Starmer stuck, even though he comes from humble roots and has down-to-earth tastes.

The son of a toolmaker, as he mentioned repeatedly in speeches, he loves soccer — still plays the sport at 63 — and enjoys nothing more than watching his beloved team Arsenal over a beer in his local pub.

He and his wife Victoria, who works in occupational health, have two teenage children they strive to keep out of the public eye.

First elected to Parliament in 2015, he was picked to lead and rebuild Labour five years later after the party's worst election result since 1935.

Starmer dragged Labour toward the political centre after taking over from veteran socialist Jeremy Corbyn, who led Labour to election defeats in 2017 and 2019.

Starmer ditched some of his predecessor's more left-wing policies and apologised for antisemitism that an internal investigation concluded had been allowed to spread under Corbyn.

Starmer's forensic and prosecutorial skills were on display in Parliament, where he tormented the three Conservative prime ministers he faced off against. He was especially scathing in attacks on Boris Johnson, who allowed parties inside Downing Street during the COVID-19 pandemic, in violation of the country's lockdown rules.

But being prime minister required a different skill set and Starmer often fell short, lacking the flexibility and political instincts that the job requires – at least on the domestic front.

Starmer seemed far more comfortable dealing with international events, notably in rallying European support for Ukraine in its war with Russia and in working to mitigate the economic and political turmoil unleashed by the U.S.-Israeli war on Iran.

That conflict opened a rift between Starmer and Trump, with whom he had initially forged a friendly relationship despite their divergent politics.

“He's liberal, which is a bit different from me, but I think he's a very good person and I think he's done a very good job thus far,” Trump said in January.

Initially reluctant to criticize Trump publicly, Starmer began taking a firmer stand after the US president's threats to take over Greenland. Starmer's critiques became sharper after the start of the Iran war, and by March Trump was deriding him as “not Winston Churchill” and mocking the Royal Navy.

Starmer's decision to largely keep the UK out of the war chimed with the public mood but did not revive his party's support.

Many Labour lawmakers were elected in their constituencies with relatively slim majorities and became increasingly anxious as Labour's poll ratings sank. Starmer's personal approval rating fell to among the worst of any prime minister.

For many Labour lawmakers, the Mandelson-Epstein revelations were the final straw because they shone a spotlight on Starmer's lack of judgment.

There was considerable anger that the prime minister appointed Mandelson to such a sensitive and high-profile post. Starmer sacked Mandelson after a first batch of emails was published in September that showed Mandelson remained friends with Epstein after the late financier's 2008 conviction for sex offenses involving a minor.

But the emails made public in January 2026 suggested that Mandelson also passed on sensitive — and potentially market-moving — government information to the disgraced financier in 2009, when he was a member of the Labour Cabinet.

Mandelson has been arrested and questioned by police on suspicion of misconduct in public office, but has not been charged, and does not face any allegations of sexual misconduct.

Then came the revelation that Mandelson had been appointed despite failing security checks for the ambassador's job. Starmer's apology for the appointment and insistence he hadn't known about the failed security vetting increasingly fell on deaf ears.

In the House of Commons on April 28, Labour lawmaker Emma Lewell said she felt “let down, disappointed and angry,” calling Mandelson's appointment “a fundamental failure of judgment.”

After Labour was handed a drubbing by voters in May's local and regional elections, the party took action. A Labour lawmaker in Greater Manchester stepped down so Burnham could run for a seat in Parliament.

He won decisively and called the moment a “turning point” for British politics. Days later, Starmer announced his intention to step down.