Andy Burnham was on Tuesday striding towards becoming the UK’s next prime minister, winning the backing of the country’s largest union, adding to an already unassailable lead in Labour’s leadership contest.

The former Manchester mayor, so far the only candidate to be the party’s new leader, had notched up 349 nominations from fellow MPs late on Monday — making it mathematically impossible for any challenger to defeat him.

The 56-year-old is bidding to replace Keir Starmer, who announced his resignation last month, bowing to months of internal pressure to step down after a series of scandals, missteps and policy U-turns in his two-year tenure.

The Unison trade union, the largest in Britain with more than 1.3 million members, said on Tuesday it was throwing its weight behind Burnham.

“He has a tough task ahead, but he is a strong, powerful voice who commands respect,” said Unison chairwoman Linda Hobson.

Under party rules, Burnham, once dubbed the “King of the North” for his staunch backing of Manchester, must also win the backing of two more Labour-affiliated organisations.

Centre-left Labour has 403 MPs in the lower house of the UK parliament, giving it a commanding majority in the 650-seat House of Commons. Its new leader will therefore become the next prime minister.

The nominations from MPs will close on Wednesday evening, and will be followed by a 24-hour vote from other groups affiliated to the party, including other unions, which ends at 6pm (10pm PKT) on Thursday.

A special leadership conference is to be held on Friday to crown Labour’s new leader, but details have so far been kept under wraps.

Burnham would then replace Starmer, earning the keys to 10 Downing Street on Monday, shortly after meeting King Charles III to be asked to form the next government.

He will become Britain’s seventh prime minister in a decade.

Burnham has said he is “deeply grateful” for the across-the-party support from Labour MPs “who have put their trust in me”.

“That is the circuit breaker I am offering: power out of Westminster, an economy rewired for ordinary people, and good growth in every postcode.”

Economy priority

Bank of England boss Andrew Bailey said on Tuesday that if he had one piece of advice for the next prime minister, it would be that “the big issue is growth in the economy”.

“We’ve had low growth in the economy now for the best part of 16 to 17 years,” he told parliament’s Treasury committee. “We will not get growth if we don’t have financial stability,” he said, pointing to the upheavals caused by the US-Iran war.

Burnham told Labour MPs late Monday in an online party hustings that his priorities included devolving power to communities and improving growth across the country, UK media said.

On Tuesday, he was reportedly due to appear in parliament with Starmer to hail the passage of a new law championed by the families of those who died in the 1989 Hillsborough football stadium [disaster](https://The 96 Liverpool fans who died in the Hillsborough football stadium disaster were unlawfully killed).

It aims to prevent cover-ups by requiring public officials, such as the police and intelligence services, to be transparent during investigations and inquiries into state failures.

A total of 97 people died after a crowd surge at one end of Sheffield Wednesday’s ground hosting Liverpool supporters for an FA Cup semi-final tie in 1989.

Football fan and Everton supporter Burnham, who was born in Aintree near Liverpool, was deeply affected by the tragedy and, as sports minister in 2009, pushed for a fresh inquiry into the deaths.

“Today belongs to the Hillsborough families. They never gave up,” he wrote on X on Tuesday. “Because of them, our country is one step closer to ensuring no family has to fight so long for truth and justice again.”