A parliamentary by-election in Gorton and Denton, long considered a safe seat for the Labour Party, has become a major political test for Prime Minister Keir Starmer. Polls suggest Labour is locked in a tight race with the right-wing populist Reform party and the Green Party, raising the possibility that Labour could even finish third in a constituency that helped deliver Starmer’s 2024 general election victory.

The campaign has grown increasingly bitter, with accusations of broken election laws, racial hatred and misleading materials. Labour has accused the Green candidate of attempting to manipulate Muslim voters with campaign literature referencing Gaza, while Reform suspended an activist over racist and antisemitic online posts. Starmer has framed the contest as a choice between Labour and Reform, attacking Reform leader Nigel Farage and denouncing what he called politics of grievance and division.

The result could carry consequences far beyond a single seat. A Reform win would bolster its momentum and suggest Starmer’s tougher immigration stance has failed to win over right-leaning voters. A Green victory would signal frustration among progressive voters who believe Starmer has not advanced a sufficiently left-wing agenda. Even though one seat will not shift the balance of power in Parliament, a Labour defeat could intensify scrutiny of Starmer’s already fragile leadership and potentially trigger internal unrest within his party.