Andy Burnham has officially been crowned Labour leader, and he's got a plan - though he's keeping the details to himself for now. In a speech to Labour MPs and supporters, the former mayor of Greater Manchester declared he would deliver the biggest change in British politics in four decades, which is a bold claim from a man who's been in politics for most of those decades.

Burnham pledged to give "hope back" to working-class communities, whom he says the political class has abandoned. He also outlined his plan to devolve power from Westminster to the regions, presumably so that more people can experience the joy of local government meetings.

The MP for Makerfield - who secured the leadership after being backed by 379 Labour MPs and all 11 affiliated trade unions - will take over as prime minister from Sir Keir Starmer on Monday. This marks a rapid rise for Burnham, who only won his by-election last month. (Note to self: if you want a promotion, lose an election first, then win a by-election.)

In his first speech as leader, held at the TUC headquarters in London, Burnham rejected the "neoliberal" policies of the past 40 years - including, awkwardly, some he was part of while in government - and vowed to reindustrialise the country. "Britain took a series of wrong turns in the 1980s," he said. "Political power was centralised and economic power was privatised. The country surrendered control of the essentials." He didn't mention that the 1980s also gave us leg warmers, so maybe not all bad.

Burnham urged Labour MPs to form a "one Labour team," warning: "We won't beat Britain's new right if we are consumed by infighting and pulling in different directions." He promised his approach would be "problem-solving rather than point-scoring," which is a refreshing change from the usual political sport of blaming the other guy.

On the cabinet front, Burnham said he's made no decisions yet but promised it would reflect "all parts of our party" and "all communities." Speculation is rife that Ed Miliband and Shabana Mahmood are in the running to replace Rachel Reeves as chancellor, though neither has confirmed whether they can find the Treasury's secret chocolate stash.

Since announcing his candidacy, Burnham has been light on policy specifics - Friday's speech was no exception - but he promises details will come once he's settled into his new office at No. 10. "I haven't got everything right and I'm sorry where I've fallen short," he admitted. "But I have always given it my all and I always will." He also claimed to have a plan, which is more than most of us can say on a Monday morning.

Linda Hobson from Unison said the union looks forward to working with Burnham to "bring about the transformation so desperately needed for the UK." Given that Labour has trailed Reform UK in opinion polls for nearly 18 months, supporters are hoping Burnham's arrival will reverse their fortunes - or at least make the polls less depressing to read.

Sir Keir Starmer resigned last month after heavy losses in local elections and Burnham's by-election win left him facing widespread calls to step aside. Burnham paid tribute to Sir Keir, praising his record on workers' rights, renters' rights, reducing NHS waiting lists, and bringing rail back under public control. So basically, Burnham is thanking him for doing all the hard work first.