Sir Keir Starmer's absence at his first by-election as Prime Minister may signal an early defeat, backed up by polling data. The will not join Labour candidate Karen Shore on the campaign trail for the by-election on May 1 in Runcorn and Helsby, where Reform came second at the 2024 general election.

However, in polling for Runcorn and Helsby in mid-March this year, with a 40% share compared to 35% for Labour in the Lord Ashcroft polls. This marked a drastic shift in opinion from the 2024 general election, when Farage's party won 18% of the vote compared to a landslide 52.9% for Labour. This will be the first time in almost two decades a leader will not join their party's first defensive by-election, since Gordon Brown was absent in 2007 at the Labour win in Ealing Southall, although that was down to the seat being seen as an easy win for the then-governing party.

This time however, politician and pollster Lord Hayward predicts Starmer's absence could be an effort to distance himself from potential defeat.

He told : "If you have the Prime Minister there, you immediately associate him with the campaign, not only in terms of negative overall aspects, but it then raises certain specific issues in people's minds, whether that be the winter fuel allowance or whether it be... penalising farmers or aid, welfare cuts, etc."

He added: "There is a risk by having that particular person, in this case, the Prime Minister, that you actually draw attention to an issue which you would prefer not to draw attention to."

Labour is entering the with the lowest approval ratings on record for any prime minister's first contest, at a net approval of -29 percentage points.

This contrasts the Labour party's last entry at +16 percentage points with Gordon Brown, and previously at +59 for Tony Blair.

There has been a clear correlation between by-election results and public satisfaction over the past decade.

Conservatives only won one out of 11 by-elections when defending a seat with a similar or lower approval level as the -29% currently held by Keir Starmer.

Runcorn and Helsby is a new constituency that was only created in time for the general election in July 2024, made up of Halton and the former constituencies of Weaver Vale, Ellesmere Port and Neston, Eddisbury, and City of Chester.

The by-election on May 1 follows the arrest of Mike Amesbury, who was convicted earlier this year of assaulting a constituent.