Andy Burnham is now the leader of Britain's Labour Party and the country's new prime minister, after winning a leadership contest in July 2026. He became the party's third leader in under a decade. It was his third try for the top job. He was the only Labour member of Parliament running in the race. Before returning to national politics, Burnham served as mayor of Greater Manchester. He officially won the leadership around July 17, 2026. A key boost came from UNISON, Britain's largest public service union, which backed him on July 15. Bridget Phillipson and Lucy Powell ran for the deputy leadership position in the same contest.

Burnham replaced Keir Starmer, whose time as prime minister lasted just over two years. Starmer had led Labour to a huge election win in 2024, when the party took 412 seats in Parliament — close to the 418 seats Tony Blair won in 1997. But Starmer's popularity then collapsed. His approval rating dropped from -3 when he started to -66 by September 2025. That was the lowest score Ipsos, a polling company, had ever recorded for a British prime minister since it began tracking in 1977. Only 13% of Britons were happy with how Starmer was doing the job. Chancellor Rachel Reeves also hit a record low in the same poll. By November 2025, Labour's share of voter support had fallen to match the lowest level the party had ever reached, a record previously set in May 2009. Eight in ten Britons said the country was getting worse to live in. A rival party, Reform UK, was ahead of Labour by 12 points in that September 2025 poll.

On July 19, The Guardian published a data-driven look at the challenge facing Burnham. That article focused on the groups Starmer had pushed away — especially leftwing voters and trade unions. Trade unions are organisations that represent workers in dealings with employers. The decline in union support for Labour is not just a Starmer problem: The Guardian's charts show union donations to Labour have been falling for 20 years. But the drop got much worse under Starmer. In 2025, union donations hit their lowest level for any full year on record.

Eleven trade unions are officially linked to the Labour Party, and the relationship has been strained repeatedly. In July 2022, Starmer fired a senior party figure named Sam Tarry for giving TV interviews from a rail strike picket line — a sign he wanted to keep his distance from strike action. In 2023, the head of Unite, a major union, said her union's support for Labour was not a "blank cheque." Things got worse from there. In July 2025, Unite suspended the Labour Party membership of Angela Rayner, Labour's deputy leader, over a dispute about bin strikes in Birmingham. In March 2026, Unite cut the fees it pays to Labour by more than half a million pounds. A recent poll showed Labour and Reform UK tied at 28% among trade union members — a 20-point drop in union support for Labour since the 2024 election.

Unions in the energy sector also turned against Starmer. The GMB and Prospect, which represent tens of thousands of energy workers, criticised his climate policies. But Starmer's government did pass a major employment rights bill — a law strengthening protections for workers — that unions called a "generational shift." That law received final approval from the House of Lords in December 2025. Even so, that achievement did not stop the broader decline in the Labour-union relationship.

Burnham's own past with the unions is complicated. In the 2015 Labour leadership election, the Unite union picked Jeremy Corbyn as its first choice and Burnham as its second. The fact that Burnham was not the unions' favourite back then, but won enough union support to take the leadership in 2026, suggests a shift in the movement — one where who else is running matters as much as who unions actually prefer.

The broader context here is that Burnham takes over a party whose support has broken apart in several ways at once. Leftwing voters felt alienated by Starmer's move to the political centre. Union members felt ignored. And Reform UK, a right-leaning party, has gained ground even among trade union members, who used to be one of Labour's most loyal groups. The Guardian's data suggests the 20-point drop in union backing is not just a blip in the polls but a real shift in loyalty, with Reform UK now level with Labour at 28% among union members. The employment rights law gives Burnham something to point to as proof Labour delivered in government. But whether that argument can overcome people's daily experience of dissatisfaction, and the feeling shared by 80% of Britons that the country is heading in the wrong direction, is the central question Burnham faces.

Burnham's third attempt at the leadership worked where two earlier tries failed. But the way he won — through union endorsements, a return to Parliament from Manchester, and a contest where he was the only Labour MP standing — suggests the party rallied around him not out of excitement but because the alternatives had narrowed. Whether he can turn that fragile mandate into a rebuilt coalition, or whether the cracks that opened under Starmer have deeper roots that will outlast any single leader, is the question the Guardian's data raises but cannot answer.