Andy Burnham is set to outline his economic agenda in his first major speech since returning to Westminster, as prepares to become prime minister in the weeks ahead.The former mayor of Manchester, who will almost certainly replace Sir Keir Starmer in No 10 next month, is expected to “put rocket boosters” on key issues such as devolution in the opening weeks of his premiership.His address on Monday, one week after he was sworn in as an MP following his victory in Makerfield, is expected to set out his vision for a radical devolution of power and financial control away from Whitehall.Mr Burnham has long championed the decentralisation of powers to local authorities, and is said to be planning to boost economic growth by granting regional mayors enhanced authority over social housing, welfare, and post-16 education.His plans are similar to those laid out in his book, Head North, which advocated for a "more balanced approach, where councils and mayors were dealt some cards too".Andy Burnham is expected to set out his economic agenda in a major speech next week. (Peter Byrne/PA) (PA Wire)According to The Times, Mr Burnham is expected to argue that his plans will make the whole country better off as he seeks to stop London ‘paying the price’ for economic failure in the North.On Sunday, housing minister Steve Reed, who is backing Mr Burnham to be the next prime minister, rejected suggestions he had indicated he wanted London to subsidise the rest of the nation.“First of all, that’s not what he’s saying,” he told Sky News. “What Andy is saying is that this is one of the biggest economies on the planet, and yet we have some of the poorest regions in Europe in this country, and that is because of the grotesque regional economic inequality we have in this country.”He added it “benefits the South East of England if the rest of the country does well”, claiming Mr Burnham’s plan would help ease London’s housing crisis. “It doesn't help London if London is the only place where people see opportunities for jobs and economic growth, because people from all over the country come to London,” he said.On Sunday, housing minister Steve Reed, who is backing Mr Burnham to be the next prime minister, rejected suggestions he had indicated he wanted London to subsidise the rest of the nation (PA)“It pushes up our housing costs and pushes up housing demand. It benefits the South East if the rest of the country does well.”Mr Reed also said Mr Burnham is “committed” to Labour’s manifesto but will “want to change some things”, including on devolution.He said there would be “changes of emphasis” but suggested the “fundamentals” would remain, including the fiscal rules.Should Mr Burnham remain the sole candidate for the Labour leadership, this speech would precede his entry into Downing Street by exactly three weeks. Nominations for the leadership close on 16 July, with a formal declaration as leader anticipated the following day if he is unopposed. However, precedent dictates that the handover to the prime minister would occur on the next working day, 20 July.Former armed forces minister Al Carns has yet to rule out running against Mr Burnham in the race, telling the BBC that his economic speech would determine if he launched a bid (PA Wire)Former armed forces minister Al Carns has yet to rule out running against Mr Burnham in the race, telling the BBC that his economic speech would determine if he launched a bid."We need to see a vision, we need to see the plan because unfortunately a vision without a plan is a dream," he said."What I would like to see is where do we want to be by 2029 and where do we want to be by 2034-35."Meanwhile, Mr Burnham continues to mull his future cabinet.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 on Sunday, Labour deputy leader Lucy Powell said backed Mr Miliband as a good chancellor.Asked whether she thought he would be good at running the Treasury, she told the BBC’s Sunday With Laura Kuenssberg: “Yes I do actually, but actually I think this is a slightly distracting conversation, because I think we’ve all got a really important job to do.”She added that the cost of living should be the focus and not “tittle-tattle” about cabinet positions.