Runcorn & Helsby: Labour defending near-14,700 majority over Reform
Reform would need a swing in the share of the vote of 17.4 percentage points to gain the seat from Labour.
Mike Amesbury has triggered the process that will lead to a parliamentary by-election in Runcorn &, Helsby, a seat he won for Labour at the 2024 general election with a majority of 14,696.
It was one of the 50 largest majorities achieved by Sir Keir Starmer’s party on polling day.
Mr Amesbury took 53% of the vote, with Reform in a distant second place on 18%, followed by the Conservatives (16%), the Greens (6%) and the Liberal Democrats (5%).
He signalled his intention to stand down as an MP in a letter sent on Monday to Chancellor Rachel Reeves.
She has responsibility for initiating the procedure that allows members of Parliament to resign from the House of Commons.
Mr Amesbury is standing down after being handed a suspended prison sentence for punching a man in a street in Frodsham, Cheshire, in October.
He was suspended by Labour when footage emerged of the incident and has spent the last few months sitting as independent MP.
Runcorn & Helsby is a new constituency that was fought for the first time at the 2024 election.
Had the seat existed at the previous general election in 2019, notional data suggests Labour would have won but on a slightly lower share of the vote (49%) than Mr Amesbury achieved in 2024, with the Tories in second place.
Based on the 2024 result, Reform would need a swing in the share of the vote of 17.4 percentage points to gain Runcorn & Helsby.
This is the equivalent of a net change of 18 in every 100 people who voted Labour in 2024 switching to Reform.
The largest swing at a by-election in the 2019-24 parliament where a seat changed hands was 34.1 percentage points, from the Conservatives to the Lib Dems in North Shropshire.
A date has yet to be announced for the by-election in Runcorn & Helsby, which will be the first such contest since the 2024 general election.
It is possible Labour will schedule it to take place on May 1, the day local and mayoral elections are being held in a number of areas of England.
There were 23 by-elections during the 2019-24 parliament, of which 11 were Conservative defeats, two were Labour defeats, one was an SNP defeat and nine were held by the incumbent party.
