Labour’s projected vote share in the Holborn and St Pancras by-election on 8 October has clustered in the low-to-mid 40s across models, reflecting a drop from the 48.9% achieved by Keir Starmer in 2024. The seat fell vacant after Starmer’s resignation on 1 September, with Labour selecting Camden Council leader Sagal Abdi-Wali and the Greens fielding party leader Zack Polanski. Camden’s May 2026 local results showed Labour on 38.8% against the Greens on 28.8%, while national polling shifts under new Prime Minister Andy Burnham and the endorsement of former independent Andrew Feinstein by the Greens have narrowed the gap. Models from Electoral Calculus, PollCheck and others place Labour between 39% and 41.7%, with George Galloway’s Workers Party candidacy further fragmenting the left-leaning vote and supporting the market’s emphasis on the 40-45% band as the most likely outcome.