He was sentenced to 10 weeks behind bars after he pleaded guilty to the assault by beating of 45-year-old Paul Fellows in Frodsham, Cheshire, in the early hours of 26 October.
He announced his resignation as MP for Runcorn and Helsby in a social media post on Monday, describing the assault as a “deeply regrettable incident” for which he had “rightly been punished”.
“I am sincerely sorry to Paul Fellows, my family, colleagues and constituents,” he added.
A by-election will now be triggered in Runcorn and Helsby, where constituents will vote to elect a new MP.
Image: Mike Amesbury leaving Chester Crown Court in February. Pic: PA
By-election a ‘big test’ for PM
It will be the first by-election since Sir Keir Starmer became prime minister, in what Sky News’ political correspondent Liz Bates said would be a “big test” in a seat where Reform UK came second last year.
“Losing it would be an unmitigated disaster given the 14,000 majority achieved last time round,” said Bates.
Amesbury came first in Runcorn and Helsby with 22,358 votes at the 2024 general election – equating to 52.9% of the electorate.
Reform UK came in second with 7,662 votes (18.1%) and the Tories in third with 6,756 votes (16%).
Reform has yet to announce a candidate, but Karen Shore, the deputy leader of Cheshire West and Chester Council, will run for Labour.
The Conservatives have opted for Sean Houlston, a membership services manager for the National Federation of Builders.
Image: Sir Keir Starmer’s government has been polling very badly indeed. Pic: PA
When will the by-election be?
Under parliamentary procedure, an MP cannot simply resign but must be disqualified from holding their seat.
To do this, they must apply for a role in the paid office of the Crown, meaning they automatically lose their seat because working for the Crown is not seen as impartial.
Titles include the crown steward and bailiff of the Chiltern Hundreds and the Crown Steward and Bailiff of the Manor of Northstead.
Rachel Reeves has now appointed Amesbury to be steward and bailiff of the Three Hundreds of Chiltern, meaning the parliamentary seat is officially vacant.
Once he does, the chief whip will put forward a motion to Lindsay Hoyle, the Commons speaker, to officially begin the process of disqualifying the MP – known as “moving the writ”.
The Speaker then puts the motion to MPs for a vote. If they agree, the writ passes through the Commons and ends up with the returning officer in the local constituency who oversees the by-election.
The writ is typically issued within three months of the MP resigning from their seat and in doing so, the date of the by-election is fixed.
It could potentially coincide with the local elections in May.
Rachel Reeves has hinted that taxes are likely to be raised this autumn after a major U-turn on the government’s controversial welfare bill.
Sir Keir Starmer’s Universal Credit and Personal Independent Payment Bill passed through the House of Commons on Tuesday after multiple concessions and threats of a major rebellion.
MPs ended up voting for only one part of the plan: a cut to universal credit (UC) sickness benefits for new claimants from £97 a week to £50 from 2026/7.
Initially aimed at saving £5.5bn, it now leaves the government with an estimated £5.5bn black hole – close to breaching Ms Reeves’s fiscal rules set out last year.
Please use Chrome browser for a more accessible video player
6:36
Rachel Reeves’s fiscal dilemma
In an interview with The Guardian, the chancellor did not rule out tax rises later in the year, saying there were “costs” to watering down the welfare bill.
“I’m not going to [rule out tax rises], because it would be irresponsible for a chancellor to do that,” Ms Reeves told the outlet.
More on Rachel Reeves
Related Topics:
“We took the decisions last year to draw a line under unfunded commitments and economic mismanagement.
“So we’ll never have to do something like that again. But there are costs to what happened.”
Meanwhile, The Times reported that, ahead of the Commons vote on the welfare bill, Ms Reeves told cabinet ministers the decision to offer concessions would mean taxes would have to be raised.
The outlet reported that the chancellor said the tax rises would be smaller than those announced in the 2024 budget, but that she is expected to have to raise tens of billions more.
Sir Keir did not explicitly say that she would, and Ms Badenoch interjected to say: “How awful for the chancellor that he couldn’t confirm that she would stay in place.”
In her first comments after the incident, Ms Reeves said she was having a “tough day” before adding: “People saw I was upset, but that was yesterday.
“Today’s a new day and I’m just cracking on with the job.”
Please use Chrome browser for a more accessible video player
“In PMQs, it is bang, bang, bang,” he said. “That’s what it was yesterday.
“And therefore, I was probably the last to appreciate anything else going on in the chamber, and that’s just a straightforward human explanation, common sense explanation.”