Sir Keir Starmer has announced his resignation as Labour leader, marking the end of his tenure. He stated he will remain in his position as UK prime minister until a successor is chosen.

Pressure on Starmer had been mounting for some time, fueled by consistently low approval ratings for both himself and the Labour party. His leadership faced further significant challenges earlier this year following the release of US Department of Justice documents that revived a scandal concerning his appointment of Peter Mandelson as US ambassador.

A critical by-election defeat in February, where Labour lost a traditionally safe seat to the Green Party after Starmer prevented the then Greater Manchester mayor, Andy Burnham, from standing, turned subsequent local and national elections in May into a crucial referendum on his leadership. The results of these May elections proved disastrous, exceeding the fears of many within the party. This outcome led to the resignations of Wes Streeting as health secretary and several junior ministers.

Despite these setbacks, Starmer initially resolved to contest any leadership challenge. However, his authority continued to erode. A protracted internal dispute over defence spending earlier this month culminated in the resignation of Labour stalwart John Healey as defence secretary.

The decisive victory of Andy Burnham in the Makerfield by-election last week, where he successfully fended off a challenge from Reform UK, has now cleared a path for his return to Westminster and the initiation of a formal leadership bid. Following Burnham's election win, Starmer initially indicated he would defend his leadership. However, over the weekend, he concluded that Labour MPs desired a different leader to guide the party into the next general election.

An official timetable for the selection of a new leader has not yet been released. In his resignation speech, Starmer indicated that potential contenders would have from July 9 to July 16 to secure the necessary nominations. According to the party's rules, candidates require endorsement from at least 81 Labour MPs. Additionally, they must receive support from either 32 of Labour's 634 local branches or three affiliated organizations, including two trade unions.

If multiple candidates meet these criteria, a leadership contest will proceed, potentially leading to a new leader being selected within weeks. The departure of Starmer, a former Director of Public Prosecutions known for his meticulous, "Mr Rules" approach, signals a significant shift for the Labour Party as it navigates internal divisions and seeks to regain public trust ahead of the next general election.