LABOUR is set to face a tough by-election challenge after disgraced MP Mike Amesbury bowed to the inevitable and announced that he will quit.

Mr Amesbury has been under pressure to leave the Commons after receiving a 10-week sentence, suspended on appeal, for punching a constituent.

He said this week that he would quit “at the earliest opportunity” as it became clear that he would otherwise face a recall petition under a procedure whereby 10 per cent of electors in the constituency can force a poll.

Under the terms of his suspended sentence, Mr Amesbury must do 200 hours of unpaid work, undertake an alcohol monitoring programme, go on an anger management course and carry out 20 days of rehabilitation work, all scarcely compatible with remaining a parliamentarian.

Labour held his Runcorn and Helsby constituency in Cheshire with a majority of nearly 15,000 in last year’s general election.

However, the government’s runaway unpopularity, likely to be compounded by looming welfare cuts, has led to fears that resurgent Reform could seize the seat.

But the new divisions opening up in Nigel Farage’s party could count against that.

The poll will also be a test for the Tories, with new leader Kemi Badenoch widely seen to have failed to make an impact since her election.

It is not a seat that the Conservatives would be likely to win, but a poor result will increase pressure on Ms Badenoch and her own hard-right agenda.