Sir Keir Starmer is facing growing unrest within his parliamentary party after a fortnight of high-profile departures and controversies, with some Labour MPs warning he has only months to restore confidence or face a leadership challenge.
The government was shaken when Deputy Prime Minister Angela Rayner resigned over a tax row, prompting a hurried cabinet reshuffle. That was followed by a separate controversy over Lord Peter Mandelson's past association with Jeffrey Epstein and a rapid reversal by Downing Street after the prime minister backed his ambassador to the United States and then sacked him less than 24 hours later. MPs have said those events have prompted fresh questions about Starmer's judgment and about the party's direction ahead of next May's local elections, which some view as a make-or-break test for his leadership.
Under Labour Party rules, a leadership contest can be triggered even when there is no vacancy. Potential challengers must first secure nominations from 20% of the parliamentary party. With Labour currently holding 399 seats in the House of Commons, that threshold translates into 80 MPs. The party rulebook allows nominations to be sought by potential candidates; as the incumbent leader, Starmer would not need to seek nominations to stand and would automatically appear on any ballot.
If a prospective challenger obtains the required support from MPs, they must also secure the backing of at least 5% of Constituency Labour Parties. After achieving both thresholds, the candidate writes to the party's general secretary, Hollie Ridley, to accept nomination. An independent scrutineer would then be appointed to approve a timetable and oversee the leadership ballot.
The next stage is a ballot of party members and affiliated supporters. Members who have been within the party for at least six months prior to the ballot are eligible to vote. Affiliated supporters, such as trade union members, also participate. Voting is conducted on a "one person, one vote" basis. If a candidate receives more than half the votes on first preferences they are declared the winner. If no candidate achieves an outright majority and more than two candidates contest the leadership, votes are redistributed according to preferences indicated on the ballots until one candidate secures a majority.
The winner of the membership ballot would then be required to visit the King to be confirmed as prime minister if they were different from the incumbent. Party officials would manage the transition timetable in accordance with Labour's internal rules and the independent scrutineer's directions.
Labour figures consulted by the party have told colleagues that the result of next May's local elections will be a critical indicator of public support. Starmer entered Downing Street in July last year with a large Commons majority; critics within his party say a sustained poor showing in local contests could increase pressure on MPs to pursue a formal challenge. Supporters of the prime minister argue that midterm electoral setbacks are not uncommon and stress the need for time to implement "phase two" of the government's agenda.
The mechanics of a leadership challenge are clearly laid out in Labour's rulebook, but political calculations about timing, candidate viability and membership sentiment would shape any attempt to unseat an incumbent. To move from disquiet to a formal contest, a would-be challenger must marshal both parliamentary and grassroots support, meet procedural requirements and win a wider vote of members and affiliates.
Any development toward a leadership ballot would be overseen by the party's general secretary and an independent scrutineer and would follow the timetable those officials approve. Until such thresholds are met or a formal challenge is declared, Starmer remains leader of the Labour Party and prime minister, accountable both to his parliamentary party and to the electorate at the ballot box.