Wes Streeting's resignation as health secretary has thrown the future of the Labour leadership into further doubt after days of mounting speculation about the prospect of a challenge to Sir Keir Starmer's position.Will a Labour leadership contest be triggered?Who else could stand in any contest, and when?How would a Labour leadership contest work?Can Sir Keir hold on to power?

Wes Streeting's resignation as health secretary has thrown the future of the Labour leadership into further doubt after days of mounting speculation about the prospect of a challenge to Sir Keir Starmer's position.Will a Labour leadership contest be triggered?Who else could stand in any contest, and when?How would a Labour leadership contest work?Can Sir Keir hold on to power?