Burnham faces by-election hurdle before any Labour leadership bid

Andy Burnham’s first obstacle is not Sir Keir Starmer. It is Makerfield, the Labour seat held by Josh Simons since July 2024, where any return to Westminster would have to survive a by-election Labour cannot afford to lose easily. Burnham left the Commons on 3 May 2017, so he must first win a seat before he can even enter the leadership race.

That matters because Labour’s rules are clear on who can challenge Starmer. A leadership contest can only be triggered if the leader resigns or if a challenger secures the backing of 20% of Labour MPs, a threshold raised from 10% in 2021. Candidates must already be MPs, and the Labour National Executive Committee sets the timetable for any ballot. Burnham, who is no longer in Parliament, would need the NEC to approve him as a candidate in Makerfield and then win the seat before any leadership run could begin.

The by-election itself would be a hard test. Simons won Makerfield in the 2024 general election with 45.2% of the vote and a majority of 5,399, while Reform UK took 31.8%. Nigel Farage said Reform would throw “everything” at the contest, a warning that Burnham could be denied a route back into Parliament even if Labour clears him to stand.

If Burnham did get into the Commons, the next hurdle would still be steep. He would need 20% of Labour MPs to nominate him to challenge Starmer. That process exists to stop casual revolts from becoming instant leadership crises, but it also means any attempt to replace a sitting prime minister depends on building a parliamentary bloc first, not just a wider party mood.

The rules tighten further if the leadership becomes vacant while Labour is in government. In that case, the Cabinet, in consultation with the NEC, appoints one of its members as acting party leader until a ballot is organised. Constituency Labour parties and affiliates then add nominations before members vote, meaning a rushed collapse at the top would still be managed through a formal handover rather than a free-for-all.

Pressure on Starmer intensified after Labour’s poor local election results on 7 May 2026, and the manoeuvring around him sharpened on 14 May 2026. Wes Streeting resigned as health secretary, saying Starmer would not lead Labour into the next general election. Angela Rayner also said HMRC had cleared her of deliberate wrongdoing over a £40,000 unpaid stamp duty bill, removing another barrier to a possible bid and underlining how quickly the succession picture can change.

For now, Starmer’s position depends on whether Burnham can clear a constituency hurdle before he can even test the party machine. If Burnham fails in Makerfield, the leadership threat loses momentum. If he wins, Labour moves into a more dangerous phase, where the real contest will be over MPs, procedure and control of the government itself.