UK Politics: By-election opens door to PM challenge

Research evidence excerpt

UK Politics: By-election opens door to PM challenge

19 June 2026

UK Politics Economics

By-election opens door to PM challenge United Kingdom

◆ Labour’s Andy Burnham has won the Makerfield by-election, with 55% of the Elizabeth Martins

vote and a majority of 9,231 SeniorHSBC BankEconomist,plc UK

liz.martins@hsbc.com

◆ Polymarket odds of Mr Burnham being PM by end-year have risen from 69% +44 20 7991 2170

to 91%, with similar odds of Ed Miliband being Chancellor (Oddschecker)

◆ The gilt market has been remarkably sanguine, but we see scope for renewed

nerviness down the line

Facts

As widely expected and suggested by polls, Manchester Mayor Andy Burnham has won the Makerfield by-

election for the Labour party, with a vote share of 55% (up from 45% for his Labour predecessor in the

2024 general election) and a majority of 9,231.

Reform came in second, with 34.5% of the vote, then the far-right Restore party with 6.8%. While this

combined vote share is high, it is notable that even if every one of Restore’s 3,111 votes had gone to

Reform, Mr Burnham would still have won fairly comfortably.

Mr Burnham has made no secret of his ambitions to challenge PM Keir Starmer for the leadership (BBC

Question Time, BBC, 4 June 2026). This result, which compares favourably, from a Labour perspective, to

its attempts to win the nearby Gorton and Denton seat in February (chart 1) and to its performance in the

local elections, will enable him to argue that he has the ability to turn the party’s fortunes around ahead of

the next general election (due by August 2029 at the latest).

That said, a poll released earlier this week suggests that outside of Makerfield, Mr Burnham’s net

favourability rating – formerly one of the only positive ones in the entire British political establishment –