Source: Sharecast
Britain now faces up to having its seventh leader in 10 years, with former Greater Manchester Burnham the frontrunner to succeed Starmer after he won the Makerfield by-election last week with a large majority, defeating the far-right Reform and Restore parties.
Starmer's popularity had plummeted after a series of policy missteps, scandals and a disastrous showing at the May local council elections that saw Reform make large gains on largely anti-immigrant policies.
Burnham is expected to easily pass the 81 nominations from lawmakers required to run for the leadership. Wes Streeting, the former health secretary who himself resigned in protest over Starmer’s leadership, on Monday said he would not be making a challenge.
Whoever takes over faces a teetering economy, febrile divisions stoked by the extreme right racist provocations of Restore and Reform and bond markets that are skittish around more government borrowing.
In a brief statement outside 10 Downing Street, Starmer said: "The question my party is asking now is whether I am best placed to lead us into the next general election."
"I have heard the answer of my parliamentary party to that question, and I accept that answer with good grace. Every decision I’ve taken has been about putting the country I love first. That is why I will resign as leader of the Labour party."
Starmer, who was close to tears towards the end of his speech as he mentioned his wife and children, said he would ask the Labour Party's national executive committee to out a succession timetable, with nominations opening on July 9 and completed by the summer recess.
In the case of a contest, this would ensure a new leader is in place before parliament returns in September, he added. The parliamentary recess is due to start on July 16.
"I will remain in post as prime minister until the contest is complete, and I will do everything I can to ensure an orderly handover of power."
More assured on the international stage, including standing up to US President Donald Trump and refusing to drag Britain into the Iran war, Starmer’s domestic judgement was exposed when it emerged that Peter Mandelson, the controversial choice as UK ambassador to Washington, had been appointed despite failing his security vetting.
Other own-goals included restricting winter fuel payments and welfare cuts - both of which were reversed after a mutiny by backbench MPs - starting the irreversible decline in his popularity.
Reporting by Frank Prenesti for Sharecast.com