Why Britain Can Change Prime Ministers Without a General Election

Keir Starmer has resigned as Labour leader, but he will stay on as British prime minister until the party chooses a successor. Under Britain’s parliamentary system, voters elect MPs, not the prime minister, so a new party leader who can command a Commons majority can be appointed by the monarch without a general election. Labour still has a parliamentary majority, and the leadership contest is set to open on July 9, with the goal of finishing before Parliament returns from summer recess in September.

The article traces the instability back to the Brexit referendum on June 23, 2016, when 51.9% voted to leave the European Union and 48.1% voted to remain. Then-prime minister David Cameron, who had backed remaining in the bloc, resigned after the defeat. Since then, Britain has moved through a rapid succession of leaders, each shaped by the unresolved political fallout from Brexit.

Theresa May replaced Cameron without a general election, but failed to secure parliamentary backing for her withdrawal deal. After she triggered Article 50 and then called an early election in 2017, the Conservatives lost their outright majority and depended on Northern Ireland’s DUP. Boris Johnson, elected Conservative leader in 2019, won a large majority with the slogan “Get Brexit Done” and took Britain out of the EU on January 31, 2020, but later resigned amid the pandemic, Partygate and other scandals. Liz Truss followed and lasted only 49 days after her tax-cut plan sent markets into turmoil, before Rishi Sunak took over and then lost the 2024 election.

Starmer won power as the antidote to that chaos, but his government quickly came under pressure as Labour MPs worried the party was losing public support, while Nigel Farage’s Reform UK rose in the polls on an anti-illegal immigration platform. Starmer said he had heard his parliamentary party and accepted its verdict “in good spirits.” The leading contender to replace him is Andy Burnham, the Greater Manchester mayor, who could become prime minister without a public vote if Labour keeps control of the Commons.