When will Andy Burnham be Prime Minister?

Former armed forces minister Al Carns remains a possible challenger and has yet to rule himself out of the race, though it remains unclear whether he could amass the 81 names needed to get onto the ballot.

Darren Jones, the chief secretary to the prime minister, had been mooted as a candidate to test Mr Burnham’s policies.

Mr Burnham could become prime minister as soon as July 20 if he remains the only candidate to succeed Sir Keir Starmer.

If no other candidates step forward, the 56-year-old Everton fan is expected to be formally declared Labour leader at a special conference on July 17.

But it is understood he would not become prime minister immediately, with the formal handover taking place on the next working day, July 20, in line with the party’s previous practice.

Leadership hopefuls need to secure the support of 81 Labour MPs and three of Labour’s affiliated organisations by July 16 to get onto the ballot.

Mr Burnham is currently the only declared candidate for the party leadership, backed by several Cabinet ministers as well as backbench MPs.

If a challenger does emerge, a ballot of Labour party members and affiliated supporters would take place between August 6-27

Under that scenario, the final result would be announced on August 29.

Mr Burnham is continuing to mull his cabinet picks should he become prime minister.

Rachel Reeves appears to have conceded she will no longer be staying on as Chancellor, with several senior ministers including Home Secretary Shabana Mahmood and Energy Secretary Ed Miliband reportedly in the running to succeed her.

An unlikely alliance of some trade unionists and city traders have reportedly urged Mr Burnham against appointing Mr Miliband as chancellor, because they believe his net zero policies to be damaging.

But transport union the TSSA has thrown its weight behind Mr Miliband.

TSSA general secretasry Maryam Eslamdoust said: “The Labour movement needs an experienced hand as chancellor who is responsive to the needs of working people and who represents a clear break from the status quo.

“The next chancellor must be serious about growing the economy by investing properly in the infrastructure Britain needs to unlock sustainable growth.

“That growth must have tangible benefits for working people through better wages, secure jobs and rising living standards.

“We believe Ed Miliband has demonstrated that he understands the need for a different approach, one that is prepared to invest for the long term and deliver an economy that works for everyone.

“We think Ed Miliband should be the next occupant of Number 11.”