British voters cast ballots on Thursday in one of the most consequential sets of local and regional elections in decades, with Labour bracing for potentially record-breaking losses as support fragments toward both the right-wing populist Reform UK and the left-wing Green Party. Around 5,000 council seats in 136 English local authorities were up for grabs, alongside elections to the Scottish Parliament and the Welsh Senedd — the first major electoral tests since Labour's landslide general election victory in 2024.

Polling experts predicted a catastrophic night for Prime Minister Keir Starmer. The University of Oxford's Stephen Fisher forecast Labour could lose more than 75% of its seats, or roughly 1,900 council positions. Reform UK, led by Nigel Farage, was expected to make sweeping gains in Labour's traditional industrial heartlands, including councils such as Barnsley and Sunderland. Meanwhile, the Green Party — under its new, media-savvy leader Zack Polanski, the only Jewish leader of a British political party — appeared set for its best-ever election result, particularly in major cities. In Birmingham, a Labour stronghold for half a century where the city council declared bankruptcy in 2023 and a prolonged rubbish collectors' strike has left waste piling in the streets, polls pointed to Labour losing roughly half its seats. Polanski's Greens have broadened their platform beyond environmental policy to embrace left-wing causes including refugee protection, Palestinian solidarity and the nationalisation of public transport and utilities — a shift that has drawn both large numbers of new supporters and internal controversy, including the suspension of candidates over antisemitic remarks.

In Scotland, the SNP was forecast to win a fifth consecutive term in the 129-seat Holyrood parliament, though likely falling short of an outright majority and potentially needing to govern with the Scottish Greens. Labour was expected to lose ground there and, more dramatically, in Wales, where Plaid Cymru — the Welsh nationalist party — appeared on course to end Labour's long dominance of the Senedd. Wales also voted under a new purely proportional system for the first time, replacing the previous mixed electoral model.

The results are being counted across three days, with a clearer picture expected by Friday morning for English councils and Friday afternoon for Scotland and Wales. Whatever the final tallies, the elections underline a profound fragmentation of British politics. For nearly a century, Labour and the Conservatives shared dominance in a stable two-party system; that era now appears to be ending. No single party currently commands more than roughly a quarter of voters in national polls, and both Reform UK on the right and the Greens on the left are winning support from voters who feel the established parties have failed to address stagnating living standards and crumbling public services.

For Starmer personally, the stakes are existential. Labour MPs have warned that losses beyond 1,500 seats could trigger calls for a leadership change, with potential challengers including Health Secretary Wes Streeting and Greater Manchester Mayor Andy Burnham watching events closely. Starmer, who made a last-minute appeal to voters not to turn to what he called the