Videos
Short data videos on by-elections, results and our insight reports. Free to use with credit: Source: Psephology.AI (psephology.ai).
Thursday, 24 September 2026
Queen's Park by-election: Green gain from Labour in Brighton
The Greens gained Queen's Park in Brighton & Hove from Labour on 24 September 2026 with 50.1%, up 26.1 points on 2023. Labour fell to 35.3%.
Thursday, 8 October 2026
Kilburn, Denby, Holbrook & Horsley by-election: Greens win four-way fight
The Greens won the Amber Valley by-election on 8 October 2026 with 29.5%, ahead of Reform UK on 27.0%. Labour, who topped the poll in 2023 with 37.1%, fell to 15.9%.
Thursday, 8 October 2026
Holborn & St Pancras by-election: Labour hold as Polanski's Greens surge to 32.8%
Labour held Keir Starmer's former seat on 8 October 2026 with 45.2%. Green leader Zack Polanski came second on 32.8%, up 22.4 points on the Greens' 2024 share, and Labour's majority fell from 30.0 to 12.4 points.
Thursday, 1 October 2026
Hirst by-election: Labour gain from Reform UK as Reform falls 20 points
Labour gained Hirst in Northumberland from Reform UK on 1 October 2026 with 50.1%. Reform UK fell from 50.0% in May 2025 to 30.0%, and Restore Britain took 10.3% at its first attempt.
Thursday, 1 October 2026
Claremont by-election: Labour hold Blackpool seat as Reform close in
Labour held Claremont in Blackpool on 1 October 2026 with 41.8%, down 10.5 points on 2023. Reform UK, standing for the first time, took 38.2%.
Thursday, 24 September 2026
Blockley by-election: Conservative gain from Green as Green vote falls 49 points
The Conservatives gained Blockley in the Cotswolds from the Greens on 24 September 2026 with 54.7%. The Green share fell from 56.3% in 2023 to 6.9%.
Thursday, 1 October 2026
Amble by-election: Labour gain from Reform UK
Labour gained Amble in Northumberland from Reform UK on 1 October 2026 with 38.8%. Reform UK fell from 44.4% in May 2025 to 33.5%.