Labour’s candidate in the Runcorn and Helsby by-election was left red-faced after a voter brutally dismissed her on the doorstep – delivering a blunt verdict on Sir Keir Starmer in the process. Karen Shore, Labour’s candidate in Thursday’s contest, was out canvassing when she was firmly rebuffed by a resident. The voter said: “Can’t stand the man, wouldn’t vote for the man, I’m going green, bye-bye.”

Ms Shore, obviously caught off guard, responded ironically: “That was good” as the door slammed shut. The moment, caught on camera and broadcast by ITV, comes at a sensitive time for Labour, with Sir Keir himself having already admitted that the contest will be “tough”.

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.

Although Mr Amesbury secured a large majority at the General Election, recent polling suggests the race is now much tighter – with Labour facing a serious challenge from Reform UK.

Speaking to broadcasters this week, Sir Keir said: “It’s going to be tight, I know that, 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 launching a sharp attack on Reform UK, accusing the party of wanting to privatise the NHS and having a “pro-Putin foreign policy”.

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

The doorstep exchange in Runcorn will likely be seen by many as a symbol of disaffection among traditional Labour voters, with Reform and the Green Party both poised to capitalise.

Labour is not the only party under pressure. Conservative leader Kemi Badenoch has also acknowledged her party faces a “challenge”, with around half of Thursday’s local authority seats currently held by the Tories.

She has urged voters to focus on local issues, including roads and bins, and has accused Reform of misleading campaigning.

Meanwhile, the Government is said to be drawing up fresh immigration measures aimed at containing the threat posed by Reform and its leader Nigel Farage.

The Telegraph has reported plans to tighten regulation of immigration advisers, in a signal that ministers are preparing for a prolonged battle over immigration policy.

The Runcorn and Helsby result, expected late on Thursday night, will be watched closely by all parties as a bellwether for wider public sentiment just months into Labour’s new term in office.