A shock poll has predicted that Labour could cling on by the skin of its teeth in the crunch Runcorn by-election despite a massive surge in support for Nigel Farage’s Reform UK. However, even if it wins the parliamentary seat when many are predicting defeat, the pollster behind the latest bombshell survey said Labour has “nothing to be happy about”.

The final poll before Thursday’s all-important vote in Runcorn and Helsby puts Labour’s Karen Shore on 36%, compared with Reform’s Sarah Pochin on 35% and Sean Houlston, for the Conservatives, a distant third on 11%. The model by Britain Predicts estimated that Labour could win by less than 400 votes – a staggering slump from the 14,000 majority it secured less than a year ago at the General Election. Writing for The New Statesman, Ben Walker, the founder of Britain Predicts, said the knife-edge election boils down to whether Reform can get its supporters to vote.

He suggested that Reform is counting on people with an unreliable record of voting, hence the uncertainty about the final prediction.

“Turn them out, and they’ve cinched the seat. Fail, and Labour hangs on,” he said.

“The central estimate from Britain Predicts is this: a gasping lead for Labour in one of its safer seats in the country.

“The party has nothing to be happy about that. But it’s all far from guarantee. I wouldn’t put money on it.”

Sir Keir Starmer has already admitted that the election in Runcorn and Helsby is “going to be tight”.

The Prime Minister, who is also facing a difficult set of local elections on the same day, said: “Every vote will count and we are fighting for every vote.

“Most governments after a General Election face a tough set of local elections at the first opportunity afterwards, and of course, we’ve had to take tough but right decisions.”

He insisted Labour had “a positive case to tell”, pointing to NHS investment and a higher minimum wage – while accusing Reform of wanting to privatise the NHS and having a “pro-Putin foreign policy”.

But the Prime Minister’s comments have done little to stop growing concerns within Labour that its support may be soft in key areas.

The by-election was triggered by the resignation of former Labour MP Mike Amesbury, who quit after receiving a suspended prison sentence for assaulting a constituent.