Labour’s Keith Vaz, who was suspended from the Commons after he was found to have “expressed willingness” to purchase cocaine for others, will not be standing for re-election.
Mr Vaz, who has been MP for Leicester East for 32 years, said in a statement he was retiring from Parliament.
He said it had been “an honour and a privilege” to serve his constituency.
Labour leader Jeremy Corbyn said he had “made a substantial and significant contribution to public life”.
Mr Vaz was suspended for six months after a scathing report by the Commons standards commission, which found he “disregarded” the law by “expressing a willingness” to help buy cocaine for male prostitutes.
He had been re-selected as Labour’s candidate in Leicester East a few weeks before the publication of the standards report.
If he had been re-elected in 12 December’s general election he could have taken up his seat, with the suspension requiring a new vote in the next Parliament.
Labour’s ruling National Executive Committee failed to reach a decision on Mr Vaz’s future last week – but he has faced calls from Labour allies to stand down.