Last night, Labour won a dismal 1.6 percent support in the Chesham and Amersham by-election — down 11.2 percent from 2019. The party’s paltry 622 votes were a humiliation for Keir Starmer, if not a fatal blow to his ailing leadership. In truth, Labour has never done well in this seat; the Liberal Democrats were always going to be the Tories’ main challenger, and even this party’s ultimate victory — winning the seat on a 30 percent swing — ought to be seen against the backdrop of its low nationwide support. Labour’s recent defeat in Hartlepool and the risky July 1 by-election in Batley and Spen will surely do more to define Starmer’s chances of remaining leader.

Yet the Liberal Democrats’ victory could help fuel one narrative touted by some Labour-aligned commentators in recent months — a “progressive alliance” to outflank the Tories and even change the electoral system. This would help overcome a real injustice: while Boris Johnson’s Conservatives poll in the low 40 percent range, the first-past-the-post system rewards them with a massive majority in Parliament; meanwhile, their various left and centrist opponents (Labour, Lib Dems, Scottish Nationalists, Greens) lose out despite their higher combined support. If Labour has no chance of winning a seat like Chesham and Amersham, then why split the progressive vote and risk letting the Tories win?

Guardian columnist John Harris argues that the fragmentation of old electoral blocs makes this a necessity: after last night’s result, he predicted a future for English politics where Lib Dems and Greens are “parties of the suburbs/commuter towns/hipster enclaves,” “Labour the party of cities,” with the “Tories a coalition of shires & post-industrial towns.” Scottish National Party dominance in Scotland, or even independence, can almost be taken for granted. Similarly, after Labour voters apparently choosing to back the Lib Dem over the Tory in leafy Chesham and Amersham, Paul Mason declared that the “#ProgressiveAlliance is already happening, whether the Labour bureaucracy likes it or not” — a confirmation of his prognosis that this is Starmer’s only path to power.