Andy Burnham will promise to give people “more breathing room” when he gives his first speech as prime minister outside No 10 on Monday.
He is expected to say he is “acutely conscious” of the UK’s high turnover of prime ministers – and that politics needs to be more stable and responsible.
And he is expected to characterise the moment as one of “reflection and resolution”, arguing Britain must be honest about the challenges it faces.
Burnham will officially replace Sir Keir Starmer and become the UK’s 59th prime minister – and seventh in 10 years – on Monday, following a meeting with King Charles III.
Earlier, Conservative leader Kemi Badenoch said the incoming prime minister was a “people pleaser” at a time when the country needed someone who could “take tough decisions, who can face down Labour MPs”.
“The job is not a popularity contest. It is making the lives of all of the people outside this building better. And he has not said what he’s going to do. It’s all airy-fairy stuff,” she said.
Burnham was officially declared Labour Party leader on Friday following a short contest in which he was the only candidate, having secured the backing of 379 MPs.
Some opposition parties have urged Burnham to call a general election in order to ensure he has a mandate for his premiership.
However, earlier Labour’s deputy leader Lucy Powell insisted Burnham would stick to the promises made in Labour’s manifesto in the 2024 general election but will be more ambitious.
“He really understands the bigger, bolder measures that are needed to live up to the manifesto promises,” she told the ‘s Laura Kuenssberg programme.
In his maiden speech on Monday morning, Burnham will reportedly set out his domestic priorities.
The Makerfield MP and former mayor of Greater Manchester is expected to argue that political stability must deliver “tangible” improvements along with “giving people more breathing room” on the cost of living.
But it is not yet clear who Burnham will appoint in his top team. He is expected to start appointing his senior ministers once inside No 10.
There has been fevered speculation as to who will get which job, particularly the crucial position of chancellor.
Energy Secretary Ed Miliband had initially appeared the most likely candidate, but in recent days Home Secretary Shabana Mahmood has emerged as another potential replacement for Rachel Reeves at the Treasury.