Imran Ahmad Khan, who was convicted of sexually assaulting a 15-year-old boy, has said he will resign as the Wakefield MP.
This has triggered a by-election in the West Yorkshire seat, which was formerly a traditional Labour stronghold.
The resignation will be test of Sir Keir Starmer’s ability to rebuild the Red Wall and marks a major opportunity for Labour.
In a statement, he said that his constituents had already been without visible parliamentary representation for a year and cited legal delays as the reason for this.
“Even in the best case scenario, anticipated legal proceedings could last many more months,” he said.
“Consequently I am resigning as MP for Wakefield and withdrawing from political life.”
Jurors found Khan was guilty after hearing evidence about how he forced the teenager to drink gin and tonic, dragged him upstairs, pushed him on to a bed and asked him to watch pornography before the attack at a house in Staffordshire in January 2008.
Khan denied sexually assaulting the 15-year-old boy.
He was originally suspended from the Tory party ahead of the verdict.
The former MP claimed he only touched the teenager’s elbow when he “became extremely upset” after a conversation about his confused sexuality.
Prosecutor Sean Larkin QC told jurors there was a different allegation against Khan, which is not part of the charge they are trying him on.