In January 2026 a committee of Labour’s National Executive Committee blocked Andy Burnham, then Mayor of Greater Manchester, from standing in the Gorton and Denton by-election. In May the Labour MP for Makerfield, Josh Simons, stood down so that Burnham could seek a seat, and Burnham won the Makerfield by-election on 18 June 2026. Four days later Keir Starmer announced that he would resign as Labour leader, remaining Prime Minister until a successor was chosen.
Under Labour’s rules a candidate needed nominations from 20% of Labour MPs. Burnham was the only candidate, nominated by 379 of the party’s 403 MPs, and was declared leader without a ballot of members on 17 July. On 20 July Starmer resigned as Prime Minister at Buckingham Palace and the King asked Burnham to form a new government. No general election was held, and Reform UK’s leader, Nigel Farage, called for one.
The example shows how a Prime Minister can change in the middle of a Parliament. The King formally appoints the Prime Minister, but by convention appoints the person best able to command the confidence of the House of Commons; with a Commons majority, that is the leader of the governing party. The real choice was therefore made under Labour’s own rules, by its MPs and affiliates, and the monarch’s role was formal.
It also shows the power of party rules and party bodies. The National Executive Committee kept Burnham out of one by-election, a sitting MP’s resignation gave him another route into the Commons, and a high nomination threshold meant that broad support among MPs settled the contest with no vote by members. It revives the debate about whether a new Prime Minister needs a fresh mandate from voters.
Nigel Farage argued that Burnham had no mandate beyond the voters of Makerfield and called for an immediate election. The constitutional lawyer Robert Craig argued that voters at a general election also back a party’s leadership team and manifesto, so calls for an election are reasonable even though they are not legally required, and that Burnham’s position is weaker than earlier mid-term successors because he was not an MP or in Labour’s leadership team at the 2024 election.
On the orthodox view described by Craig, voters elect MPs, not a Prime Minister, so a party with a Commons majority can change its leader without an election. Burnham argued that whoever commands a majority of MPs has the legitimacy to lead, and said he would govern within the manifesto on which Labour won in 2024.
Changes of Prime Minister between elections usually follow a party leadership change. In 2022 Liz Truss and then Rishi Sunak became Prime Minister in this way, after Boris Johnson resigned as Conservative leader, without a general election.
Because only one candidate reached the threshold, Labour members did not vote. The result shows Burnham’s support in the parliamentary party and among affiliates, not his support among party members or the electorate.
The facts and their significance still stand.
A direct example of how a Prime Minister changes mid-Parliament through party rules and constitutional convention, and of the debate about whether a new Prime Minister needs a general election mandate.
Signed off for students.
Origin: Human-written · Reviewer: Editor
Every fact on this page has been checked against original sources.