Labour’s Andy Burnham becomes direct threat to Starmer

Andy Burnham, the popular Greater Manchester mayor, won the Makerfield by-election on 18 June with a commanding 54.8% of the vote, significantly strengthening his position to challenge Prime Minister Keir Starmer for the Labour leadership.

Burnham secured approximately 24,927 votes in the northwest England constituency, defeating Reform UK candidate Robert Kenyon (34.5%) by a majority of over 9,000 votes. The result marks a strong performance for Labour in a seat it has long held, despite national headwinds.

In his victory speech, Burnham struck a prime ministerial tone, emphasizing the need for change within Labour and outlining priorities such as making life more affordable, cutting utility bills, and driving reindustrialisation. “I did talk about the need to change Labour … and we’ve got to now take this moment and answer the challenges that have been laid down,” he said. “It is our last chance to change but we are going to take it … and we are going to lay out a new path for Britain.”

Starmer vows to fight any challenge

Prime Minister Keir Starmer quickly responded by vowing to contest any leadership bid. “If there is a contest … I will stand, and I’ve said repeatedly I’m not going to walk away,” he told staff, while warning against internal division: “The one thing we’ve got to avoid doing is plunging our party and our country into chaos by turning on each other and tearing apart our party.”

Starmer highlighted his government’s achievements, including closer EU ties, economic stabilisation, and efforts to reduce NHS waiting times. However, the by-election result has amplified existing concerns within Labour about his leadership, following heavy local election losses and Starmer’s relatively low personal popularity.

Path to a leadership challenge

Burnham’s election as an MP removes a major barrier to a formal challenge. Under Labour rules, a leadership contest can be triggered if 20% of the parliamentary party (81 MPs, including the challenger) nominate a candidate. Only sitting MPs can lead the party and serve as prime minister, so Burnham must be sworn in (expected soon) before he can formally enter the race.

Starmer retains an automatic right to stand in any contest. The process would involve nominations from local party branches and trade unions, followed by a vote among party members – potentially taking two to three months.

Key figures like former health secretary Wes Streeting have indicated they have sufficient MP backing to force a contest unless Starmer sets out a clear departure timetable. Some Labour MPs, including Burnham ally Louise Haigh, have expressed a preference for an orderly handover to avoid a damaging public battle.

Should Starmer worry?

Yes – and here’s why the pressure is mounting:

Burnham’s popularity edge: polls of Labour members consistently show Burnham as the clear frontrunner in any leadership race. His northern appeal and “king of Manchester” persona position him well to counter the rise of Nigel Farage’s Reform UK, which has been leading national polls for over a year.
Internal party fractures: roughly a quarter of Labour MPs have reportedly urged Starmer to resign. Recent ministerial resignations and poor local results have fueled perceptions that Starmer’s leadership is hindering the party’s chances of winning the next general election in 2029.
Risk of a messy contest: a prolonged leadership battle could expose divisions, damage party unity, and hand ammunition to opposition parties. Historical precedent (especially the Conservatives’ recent instability) suggests voters punish parties seen as turning inward.
Timing pressure: Burnham’s win gives momentum for a challenge before or shortly after the summer parliamentary recess (around mid-July). Delaying could allow Burnham to build further support through his mayoral role and alliances with newer MPs.

However, Starmer is not without options. He has a loyal core of supporters, an automatic place on any ballot, and the ability to frame a challenge as reckless amid external threats from Reform UK. An orderly transition – sometimes called a “coronation” – remains the preferred path for many in the party to minimise damage and present a united front.

Outlook

Burnham’s decisive victory has undeniably shifted the internal dynamics of the Labour Party. For now, Starmer’s message is clear: he intends to fight. But with Burnham now inside Parliament and public pressure building for “fundamental change,” the prime minister faces one of the most significant tests of his leadership to date.

This article is based on reporting from Reuters.

Caption: Newly elected Labour Member of Parliament for Makerfield Andy Burnham with supporters after winning the Makerfield by-election, in Wigan, Britain, 19 June 2026. Mayor of Greater Manchester Andy Burnham beat Reform candidate Rob Kenyon by 9,231 votes, securing 54 percent of the overall vote. EPA/ADAM VAUGHAN