Voters in Holborn and St Pancras are choosing a new member of parliament in the first by-election test for Prime Minister Andy Burnham, with Labour defending the former seat of Keir Starmer against a Green Party challenge that has become a measure of whether left-leaning voters are returning to Labour.
Reuters reported ahead of Thursday’s vote that Labour is expected to retain the seat, but the contest matters beyond the constituency because the Greens gained strongly among voters who had become dissatisfied with Labour under Starmer, particularly over Gaza and the direction of the party.
Burnham has sought to change Labour’s tone on several issues, including Israel and relations with the European Union. The by-election offers an early chance to see whether those shifts are changing behaviour among voters who moved to the Greens or considered doing so.
A safe seat can still produce a useful political signal
By-elections rarely map perfectly onto national elections. Turnout is usually lower, local campaigns matter more and voters can use the contest to send a message without choosing a government. But those differences are precisely why they can reveal intensity: which voters are motivated enough to show up and which party can mobilise them.
Holborn and St Pancras is especially symbolic because it was Starmer’s seat. A strong Labour result would allow Burnham to argue that a change in leadership has helped consolidate the centre-left. A surprisingly strong Green result would show that the fragmentation of the left remains a structural challenge rather than a temporary reaction to the previous leadership.
The Greens are testing the limits of protest politics
Green parties often benefit when major parties disappoint voters on climate, foreign policy or public services. The harder task is converting that protest energy into durable parliamentary representation. A London constituency with a large progressive electorate is one of the places where that transition is most plausible.
The Greens have also faced controversy, including criticism of language used by parts of the party around Zionism. Such disputes can narrow a coalition that otherwise draws support from younger voters, environmentalists and people dissatisfied with Labour from the left.
Labour’s advantage is organisational depth and the expectation that it can influence government policy directly. The Green argument is that pressure from outside Labour is necessary to move that policy. Thursday’s vote tests which of those claims feels more persuasive to voters in a constituency with an unusually close connection to the party’s recent history.
Burnham’s national strategy is the larger story
The prime minister’s challenge is not simply to win a seat Labour is expected to hold. It is to rebuild a coalition broad enough to dominate the centre-left without alienating moderate voters. A sharper position on Gaza may recover some support, while a more ambitious approach to Europe may appeal to urban and younger voters. Both choices also create risks elsewhere.
That balancing act will define more than one by-election. The British right remains fragmented, which can help Labour electorally, but fragmented opposition does not guarantee enthusiasm for the governing party. Burnham needs voters who left Labour to believe the change in leadership is substantive rather than cosmetic.
The result will not answer that question on its own. It will provide an early data point. A comfortable Labour win with reduced Green momentum would support Burnham’s claim to be rebuilding the coalition. A narrow result or a Green surge would show that the political space to Labour’s left remains capable of shaping national strategy.
