Burnham said on Monday he was ‘finalising’ the Cabinet before becoming Prime Minister.

The Makersfield MP secured his sole leadership bid earlier this week after being backed by 379 Labor MPs, as well as 11 unions affiliated with the party.

He will take over from Sir Keir as Prime Minister on Monday, following a reception with King Charles III.

Asked by reporters about who will be in the cabinet, Burnham said: “I’m finalizing the decisions, and I’ll come to a conclusion soon, and then I’ll announce those on Monday.”

In his first speech as Labor leader at the TUC headquarters in central London, he said his cabinet appointments reflected “all parts of our party” and “all communities”.

He said his government would “restore hope” to working-class communities turned away by the political class, and reiterated plans to devolve power from Westminster to the states.

Devolution has been one of Burnham’s central messages since announcing his bid to replace Sir Keir.

He said that his government will bring about the biggest change in decades. He rejected the “neoliberalism” policies designed in the last 40 years, even when he was in power, and promised to expand the country to industry.

And in a message to Labor MPs, he said he would work tirelessly to build a “one-man team” culture.

“Britain’s New Right will not fail as we bicker and pull in different directions,” he said.

He added that his management approach would be “problem-solving rather than point-scoring”.

He added that he knows what he believes in and what he wants to do in government, telling the audience, “I have a plan.”