What happens if Starmer quits or is challenged?

British Prime Minister Keir Starmer’s position is under serious threat after dozens of his own lawmakers called for him to set out a timetable for his departure after heavy losses in local elections.
Several ministerial aides stepped down and more than 70 Labour lawmakers publicly called for Starmer to announce an exit plan.
Under Labour rules, a leadership challenge requires the support of 20% of Labour MPs (81 out of 403).
If only one candidate qualifies, they are elected unopposed; if more than one, the winner is decided by a ballot of party members and affiliates.
Starmer has an automatic right to be on the ballot if he chooses to fight the contest.