Starmer said that nominations to replace him as leader of the Labour Party, and thus prime minister, will open July 9 and close when Parliament breaks up for its summer recess July 16.

If no challenger emerges to Burnham, he could be in office shortly after that. If there is a contest, Starmer said, a new leader will be chosen by Sept. 1.

Starmer’s “decision marks the beginning of a transition and it is important that this process is conducted in an orderly and responsible way,” Burnham said in a statement. “I will put myself forward as part of this process.”

One of the few people who had been expected to challenge Burnham, former Health Secretary Wes Streeting, said Monday that he would in fact back his leadership bid.

In an open letter, Streeting said he was convinced the former mayor could “win the fight of our lives against the forces of nationalism.”

Streeting resigned last month as the speculation swirling around Starmer reached fever pitch.

Starmer’s decision marks an astonishing fall for a leader who led his party to a landslide election victory in 2024, riding a wave of popular discontent against 14 years of right-wing Conservative rule.

Before announcing his resignation, Starmer touted his achievements, including what he said was a stronger economy and higher wages, improvement in workers’ rights, bigger defense budgets and lifting a million children out of poverty — all “because of the choices that I made.”

But a series of bruising scandals hit him, while many of his own lawmakers blamed him for policy missteps that were deeply unpopular.

Calls for Starmer to quit have intensified since May when, after two years in power, he led his party to one of its worst-ever performances in local and regional elections, as Nigel Farage’s hard-right Reform UK made historic gains.

The leader’s key rival within the party is Burnham, the former mayor of Greater Manchester, who had openly discussed plans to bring a leadership challenge. Burnham won a special election Thursday for a seat in Parliament, clearing a crucial hurdle for him to mount such a challenge.

Starmer had vowed to fight any contest but as reports spread over the weekend, President Donald Trump even weighed in. The prime minister “failed badly on two very important subjects- IMMIGRATION AND ENERGY.”

“I wish him well!” Trump wrote on Truth Social.

‘The change moment’

Burnham, nicknamed the “King of the North” for his forceful advocacy for northern England in his role as mayor, will be the overwhelming favorite to succeed Starmer with support from the party’s MPs.

He defied political gravity to defeat the Reform candidate and re-enter Parliament with a large majority on a message of change.

“This now is the change moment,” he said early Friday after his special election victory. “We have an opportunity to turn the tide, to make the country feel like it’s working again, to make people see that politics can make a positive difference, to make people feel hope again.”