Norwich South MP Clive Lewis has withdrawn from the Labour leadership contest.
He announced his decision as the deadline for collecting votes from fellow MPs approached.
Mr Lewis had until 2.30pm on Monday to secure 22 nominations from Labour MPs and MEPs but by lunchtime had only collected five.
Mr Lewis had warned that Labour's chances of winning the next election without making alliances were slim.
He has not shied away from taking controversial stands, describing himself as a republican and calling for a referendum on the future monarchy.
Last week, the MP suggested the Duchess of Sussex had been the victim of "structural racism" in the media.
Earlier the Norwich South MP suggested the Duchess of Sussex had been the victim of "structural racism" in the media.