Andy Burnham takes office as Britain's prime minister Monday, facing mounting pressure to tackle the political and economic challenges that have brought down six predecessors in the past decade.
On Friday, delegates overwhelmingly backed the former Greater Manchester mayor as leader of the Labour Party, following Keir Starmer's resignation last month.
His top priority now will be boosting the economy and improving living standards for voters who have despaired over soaring energy and food prices since the start of the war in Ukraine.
Burnham will have little room for maneuver amid sluggish economic growth, high public debt and strict financial rules requiring him to balance government spending against tax revenue.
In a speech on Friday, Burnham said he wanted to "take us to a country where life is more affordable."
He has championed devolving power to regional hubs as a lever for growth.
"It's not just about driving local growth, it's about turning these places around so they drive national growth," explained Philip McCann, from the research organization Productivity Institute.
Burnham has said he will support smaller businesses, "reindustrialization," and greater public control over water, transport and energy.
The Financial Times reported he could ease restrictions on oil and gas drilling in the North Sea to reduce energy bills.
His pick for Chancellor of the Exchequer, yet to be announced, may well determine how left-wing or centrist his economic agenda is.
He also will need to tackle ballooning welfare costs, which Burnham has acknowledged need to be reduced.
Starmer faced backlash from the public and his party over reforms to the benefits system, including a cut to winter fuel payments for the elderly.
He had to climb down from the changes, contributing to his unpopularity.
Burnham, from the soft left of Labour, will face pressure to resist slashing benefits.
He has also pledged to "fix" underfunded sectors like social care, which he attempted to overhaul as health secretary in 2009.
On Friday, Burnham, whose father has Alzheimer's, said he was "prepared to grasp the nettle" to make changes. "The system's broken," he added.
Burnham will need to fill a £4.7-billion ($6.3-billion) gap over four years in the country's defense investment plan.
Starmer published the long-delayed plan last month, but the task of delivering it will fall on Burnham.
Burnham will likely also face pressure internally and from allies, including the United States, to further ramp up defense spending and meet the NATO target of spending 3.5% of GDP by 2035.
He previously said he would take "responsibility" to fund the defense plan and make "no compromise" on defense.
A key task will be stemming the growing popularity of Nigel Farage's hard-right, anti-immigration party Reform UK.
Labour has been bleeding supporters to the Green Party and Reform UK, which made big gains in local elections earlier this year and piled pressure on Starmer to make way for a politician who could counter Reform UK's success.
In his speech on Friday, Burnham vowed to build a new political direction "that is distinctly Labour," independent of both fringe parties.
"We win by being us," he said.
"We won't try to out-Green the Green Party, or out-Reform Reform UK, or do what we have done in the past by wearing too many Tory clothes."
Tony Travers, a professor at the London School of Economics, said it could mark a different approach.
"What this signals is that the Labour Party under Burnham will want to try to win back voters from Reform UK and the Green Party with a different offer," Travers told AFP.
"In terms of international affairs, the big issue is dealing with Donald Trump," said Travers, noting Starmer had a relatively amicable relationship with the U.S. president up until the U.S.-Iran tensions.
Beyond finding his footing with the unpredictable American leader, who described Burnham as "extremely liberal," he will need to contend with wars raging in Ukraine and the Middle East.
Burnham has signaled he will not stray far from Starmer's generally well-regarded foreign policy, maintaining close ties to NATO and other allies.
"Our relationship with the U.S. will remain critical as our most important defense and security ally. And Britain's support for Ukraine will not waver," Burnham wrote in The Times this month.
