Sir Keir Starmer has announced he will step down as MP for Holborn and St Pancras, triggering a by-election, after already leaving Downing Street in July following 23 months as prime minister. He told the Camden New Journal it was the "right time" to move on and focus on international affairs, including defence, security, trade and technology, as well as continuing his work combating violence against women and girls.

Starmer took office in July 2024 after a landslide election win but saw his popularity collapse amid growing discontent within his own party. His departure from No 10 followed Labour's record local election losses and mounting backbench pressure, with the final trigger being Andy Burnham's victory over Reform UK in the Makerfield by-election, which Labour figures took as proof Burnham could beat Nigel Farage's party where Starmer could not. His premiership was also rocked by the shock resignations of defence secretary John Healey and armed forces minister Al Carns over a funding row that saw only £10bn rather than a promised £23bn allocated to the Defence Investment Plan.