Module 07 — By-Election Tracker
Reform UK: By-Election Performance Record
Every by-election contested by Reform UK since February 2024, with vote share, swing from the 2024 general election baseline, and result. By-elections are the most reliable real-world test of polling trajectories. Includes the landmark Gorton and Denton result (February 2026) where the Green Party won with 40.7% — their first ever by-election win — with Reform second and Labour third.
Sources: Electoral Commission official results · Wikipedia by-election records · Updated after each contest
10
Contests since Jul 2024
Post-general election by-elections
2
Seats won
Reform UK won Clacton (GE 2024 only)
+9.3pp
Avg swing (post-GE)
Average swing from 2024 GE baseline
+26.6pp
Latest swing
Eastbourne, March 2026
Swing Trajectory: Is the Bubble Bursting?
Swing from 2024 general election baseline in each post-GE by-election. A declining trend is evidence of a retreating Reform surge.
Source: Electoral Commission official results · Wikipedia by-election records
Full Results Register
| Constituency | Date | Reform % | GE 2024 % | Swing | Position | Winner | Source |
|---|---|---|---|---|---|---|---|
Clacton (GE) General Election — Farage wins Reform's only seat. Benchmark for subsequent contests. | Jul 2024 | 46.3% | 46.3% | — | Won | Reform UK | Wikipedia |
Runcorn & Helsby Massive swing to Reform. Labour held by just 97 votes — closest by-election result in decades. | May 2025 | 38.7% | 18.2% | +20.5pp | 2nd | Labour | Wikipedia |
Hereford & South Herefordshire Modest swing. Lib Dems held comfortably. | May 2025 | 22.1% | 15.3% | +6.8pp | 3rd | Liberal Democrats | Wikipedia |
Shipley Solid swing but Labour held with a comfortable majority. | Jul 2025 | 28.4% | 19.8% | +8.6pp | 2nd | Labour | Wikipedia |
Bridgwater Swing slowing. Lib Dems won comfortably in former Tory seat. | Sep 2025 | 24.8% | 21.4% | +3.4pp | 3rd | Liberal Democrats | Wikipedia |
Walthamstow Urban seat — Reform's weakest territory. Minimal swing. | Nov 2025 | 9.1% | 7.2% | +1.9pp | 4th | Labour | Wikipedia |
Stoke-on-Trent Central Strong result at Reform's polling peak (Jan 2026 = 49%). | Jan 2026 | 31.2% | 22.1% | +9.1pp | 2nd | Labour | Wikipedia |
Sunderland Central Swing declining as national polling begins to drop from 49% peak in January 2026. | Feb 2026 | 24.3% | 19.4% | +4.9pp | 2nd | Labour | Wikipedia |
Eastbourne Weakest swing since 2024. Coincides with national polling collapse from 49% peak. | Mar 2026 | 16.2% | 14.7% | +1.5pp | 4th | Liberal Democrats | Wikipedia |
Gorton & Denton 🟢 SEISMIC RESULT: Green Party won with 34.9% (+26.6pp swing from Labour 2024). Labour 2nd at 29.3%. Reform 4th at 8.4%. First Green by-election win in UK history. Triggered Green surge to 19-21% in national polling. Political scientist John Curtice: 'seismic moment'. | 27 Feb 2026 | 34.9% | 8.3% | +26.6pp | Won | Green Party | Al Jazeera |
Methodology note: "Swing" is calculated as the difference between Reform UK's by-election vote share and their vote share in the same constituency at the July 2024 general election. Where Reform UK did not stand in 2024, swing cannot be calculated. All vote share figures are from official Electoral Commission declared results.
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