Green Party leader Zack Polanski has been confirmed as the party’s candidate for the upcoming Holborn and St Pancras by-election, setting up a closely watched political contest in central London.

The by-election is scheduled for 8 October 2026 after the seat was vacated by former Labour Prime Minister Keir Starmer. Labour has selected local council leader Sagal Abdi-Wali as its candidate.

The Greens are hoping to turn their recent electoral momentum into a parliamentary breakthrough. The party won more than 10% of the vote in the constituency at the 2024 general election, while an independent candidate campaigning over the Gaza conflict received around 19%.

Polanski said the Greens would enter the contest as the underdogs, but argued that the party now has momentum and an opportunity to challenge the established parties.

The result could attract national attention well beyond the constituency. A strong Green performance would increase pressure on Labour in London and strengthen the party’s argument that it can compete for Westminster seats.