Imran Ahmad Khan has resigned as an MP after he was found guilty of sexually assaulting a 15-year-old boy.
Khan, who represented Wakefield in West Yorkshire, had been resisting calls to stand down since he was thrown out of the Conservative Party when he was convicted on Monday.
But he said it was “intolerable” for voters in the constituency to lack representation while he appeals and said stepping down would allow him to “focus entirely on clearing my name”.
Boris Johnson now faces a potentially challenging by-election in Wakefield.
In a statement posted to Twitter, Khan said: “While legal proceedings are ongoing, I do not believe that it would ordinarily be appropriate to resign.
“However, owing to long delays in the legal process, my constituents have already been without visible parliamentary representation for a year. Even in the best case scenario, anticipated legal proceedings could last many more months.
“I have therefore regrettably come to the conclusion that it is intolerable for constituents to go years without an MP who can amplify their voices in Parliament.”
He said his constituents “deserve better than this” and therefore he was resigning as MP for Wakefield and “withdrawing from political life.”
Labour held Wakefield from the 1930s until Khan’s victory in the 2019 general election.
His resignation sets up a tough battle for the Tories, as the prime minister fights to remain leader after he was fined for breaching his own coronavirus lockdown laws.
Political correspondent
Labour had known for months a pivotal by-election battle could be on the cards as a result of Imran Ahmad Khan’s trial, and behind the scenes they have been preparing for it.
With Khan’s resignation as an MP, the fight for the marginal red wall seat of Wakefield is on.
It will be a key test for the leadership of Sir Keir Starmer, offering the possibility of the first Labour by-election win from the Tories in a decade.
The constituency backed Brexit by 63%. This was one reason why the vocally pro-EU Labour incumbent Mary Creagh lost her seat in 2019 – its first time in Conservative hands since the 1930s.
Ms Creagh is not expected to stand in the city again, but is still understood to be keen to return to Westminster.
Sources in the Labour Party are optimistic about their chances of victory. Without Jeremy Corbyn’s leadership or Brexit, and with a cost-of-living crisis, they argue Wakefield is winnable.
The Conservatives will be hoping their new campaign infrastructure and investment in the region will bolster their effort.
They also, however, face difficult questions about warnings Khan’s victim claims he made ahead of the 2019 election, which seem to have been ignored.
Khan was only chosen to stand for the Tories in the West Yorkshire seat after the original candidate stood down over the emergence of racist and sexist Facebook posts.
During the trial at Southwark Crown Court, the jury heard Khan forced a 15-year-old boy to drink gin and tonic at a party before he dragged the teenager upstairs, pushed him onto a bed and asked him to watch pornography before the attack.
The victim, now 29, said Khan touched his feet and legs and the MP came within “a hair’s breadth” of his privates as he tried to sleep in a top bunkbed.
He ran to his parents and a police report was made at the time, but no further action was taken because the youngster did not want to make a formal complaint.
But he told jurors “it all came flooding back” when Khan stood as a Conservative in the December 2019 general election.
He said he was not “taken very seriously” when he made the allegation to the Conservative Party press office days before Khan was elected as MP for Wakefield in the December 2019 general election.
He made a complaint to the police days after Khan helped Mr Johnson win a large Commons majority by taking Wakefield.
Khan was found guilty by a jury after five hours of deliberations.
Janes Solicitors, the firm representing Khan, said he “maintains his innocence” and “will be appealing as soon as possible”.