From leftwing voters to unions: can Burnham win back Labour bases lost by Starmer? – visualised

Composite: Prina Shah for the Guardian/NurPhoto/Shutterstock/AFP/Getty View image in fullscreen Composite: Prina Shah for the Guardian/NurPhoto/Shutterstock/AFP/Getty Analysis From leftwing voters to unions: can Burnham win back Labour bases lost by Starmer? – visualised Alexandra Topping and Lucy Swan As Andy Burnham enters No 10, Guardian data analysis reveals the fissures with Labour’s traditional supporters, and the traps the new PM will want to avoid Keir Starmer entered 10 Downing St on a wave of optimism after a landslide victory in the 2024 general election. His Labour party had overturned a defeat in 2019 in which the party crashed to its worst result since 1935. Labour won 412 seats, just a few shy of the 418 won by Tony Blair in 1997, a result that gave Labour a leader in office for a decade. But a little more than two years after he came to power, Starmer’s tenure is over. Over the past 24 months the popularity of the human-rights lawyer turned prime minister has plummeted, from a net approval rating of -3 when he took office, to -66 by September 2025 – the lowest net approval rating recorded by Ipsos for any prime minister since 1977. As Andy Burnham takes over, Guardian data analysis reveals where Starmer lost support – among the ranks of his own MPs and among the electorate – and provides some insight about the bear traps Burnham’s team will want to avoid. The unions When the Labour party was formed at the turn of the 20th century , it was synonymous with the trade union movement. But over the last half century the relationship has become increasingly strained, with the chart below revealing a steady decline in union donations over the past 20 years. But the chart also reveals that a fracture that opened under Neil Kinnock, and widened with Blair, continued to worsen under Starmer, reaching its lowest point for any full year in 2025. Chart showing union donations to Labour over time Starmer ran into trouble with the unions, 11 of which are affiliated to Labour, soon after becoming leader in 2020. In 2022 the then leader of the opposition sacked the frontbencher Sam Tarry for doing broadcast interviews from a rail strike picket line. A year later, Sharon Graham, the general secretary of Unite, put Starmer “on notice”, saying the support of Britain’s second-largest union should not be treated as a “blank cheque”. As a row about bin strikes in Birmingham turned increasingly acrimonious, Unite suspended the membership of the then deputy Labour leader, Angela Rayner , and in March this year it reduced its membership fees to Labour by more than half a million pounds . Unions hailed a “generational shift” for workers’ rights when Starmer’s government pushed through its employment rights bill, but there seemed to be little real warmth between the prime minister and union leaders. Two other major unions, the GMB and Prospect, who between them represent tens of thousands of energy workers, criticised Starmer’s net zero policies , while a rec