Runcorn and Helsby by-election - all you need to know

A key by-election is set to take place in the Cheshire constituency of Runcorn and Helsby.
It comes after Monday's announcement by incumbent MP Mike Amesbury that he is standing down following his recent conviction for assaulting a constituent.
That means a contest must be held to find a new MP for the constituency, which was formed just before the last general election.
A date for the by-election has yet to be decided.
Why is there a by-election in Runcorn and Helsby?
On 27 February, Amesbury was given a 10-week prison sentence and taken straight to HMP Altcourse in Liverpool.
After three nights behind bars, a judge agreed to suspend Amesbury's jail term for two years.
Under concerted pressure to quit the House of Commons, Amesbury - who lost the Labour whip after he was arrested last autumn and has since been sitting as an independent MP - agreed to stand down.
Had he not have done so, a recall petition could have been launched.
This procedure is triggered when an MP is given a custodial sentence.
If 10% of constituents sign a petition asking for their MP to be recalled, a by-election is called.
Amesbury's resignation will mean a recall petition is no longer needed.

What is the make-up of Runcorn and Helsby?
Runcorn and Helsby includes the towns of Runcorn, Frodsham and Helsby, as well as various villages and a significant rural area.
In total, 22% of the constituency is classed as a built-up area, 60% rural and 14% as water or wetland.
It has a population of 93,520, with 21% of residents under 18, 57% aged 18-64 and 21% over 65.
What is the electoral history of the constituency?
Runcorn and Helsby is a new constituency that was only created in time for the general election in July 2024.
More than half of it (51.2%) came from the former constituency of Weaver Vale, with 37.1% from Halton and the remainder from three other former constituencies - Ellesmere Port and Neston, Eddisbury, and City of Chester.
At the 2024 general election, Amesbury won Runcorn and Helsby for Labour with 52.9% of the vote, a majority of 14,696.
Reform UK came second with 18% of the vote, ahead of the Conservatives on 16%, the Green Party with 6.4%, and the Liberal Democrats with 5.1%.
Two smaller parties received 1.4% between them.
Amesbury was the Labour MP for Weaver Vale from June 2017 until the seat was abolished before the general election.
He gained the seat from Conservative Graham Evans, who had been the constituency's MP since 2010.
Meanwhile, from its creation in 1983, Halton was always held by Labour.
Derek Twigg - who is now the MP for Widnes and Halewood - held it from 1997.
Why is this by-election so important?
This will be Sir Keir Starmer's first by-election as prime minister.
A lot has happened in the eight months since Labour swept to power, with several tax rises announced in the Budget, and ongoing negotiations with President Trump about world trade and the war in Ukraine.
University of Liverpool Professor Jon Tonge recently told BBC Politics North West that, as one of the safest Labour seats in the country, it would be "quite some feat" if another party were to take Runcorn and Helsby.
If recent opinion polls are anything to go by, Reform UK may well be confident heading into the by-election, not least because they came second there in July.
The Conservatives will be hoping for signs of a recovery too. They came third in Runcorn and Helsby last time around, and they were not far off second-placed Reform.
There is a lot at stake for everyone.
When will the Runcorn and Helsby by-election take place?
We do not yet know when it will be held.
We will only be given a date once Amesbury formally stands down.
He told the BBC: "I'm going to step aside at the earliest opportunity.
"I've got processes I must go through - there's a statutory process in terms of redundancies."
Who are the candidates in the Runcorn and Helsby by-election?
In alphabetical order by candidate name:
Green Party: Chris Copeman
Labour: Karen Shore
The other major parties have not yet announced their candidates.
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