PollCheck

UK By-Elections Tracker

Results, polling and analysis for UK parliamentary and mayoral by-elections.

Last updated 9 July 2026 - Clacton by-election: writ moved, polling day not yet announced

Mayoral by-elections

30 Jul 2026 · Interactive model

Greater Manchester Mayor

Supplementary Vote
Ref 27.8%   Lab 24.9%   Grn 22.6%
2026 locals baseline · replacing Andy Burnham
Open the model ->

By-elections this Parliament

Date TBC · Writ moved

Clacton

Farage resignation - standing again
Ref 46.2%   Con 27.9%   Lab 16.2%
GE2024 result · Farage (Ref) · majority 18.3pp
Constituency page ->

18 Jun 2026 · Result

Makerfield

Labour hold
Lab 54.8%   Ref 34.5%   Oth 10.7%
Burnham (Lab) · majority 20.3pp · turnout 58.75%
Full result ->

18 Jun 2026 · Result

Aberdeen South

Conservative gain
Con 49.5%   SNP 28.6%   Ref 8.6%
Lumsden (Con) · majority 20.9pp · turnout 37.4%
Full result ->

18 Jun 2026 · Result

Arbroath and Broughty Ferry

SNP hold
SNP 41.1%   Con 19.4%   Ref 18.2%
Bird (SNP) · majority 21.7pp · turnout 31.35%
Full result ->

26 Feb 2026 · Result

Gorton and Denton

Green gain
Grn 40.6%   Ref 28.7%   Lab 25.4%
Spencer (Grn) · turnout 47.5%
Full analysis ->

1 May 2025 · Result

Runcorn and Helsby

Reform gain
Ref 38.7%   Lab 38.7%   Con 7.2%
Pochin (Ref) · majority 6 votes · turnout 46.2%
Full result ->

More for Clacton: Scenario explorer|Ward map|Constituency profile

More for Gorton and Denton: Ward map explorer|Turnout map

Results table

Date Constituency Held by Winner Turnout
18 Jun 2026 Makerfield Labour Labour (Andy Burnham) 58.75%
18 Jun 2026 Aberdeen South SNP Conservative (Douglas Lumsden) 37.4%
18 Jun 2026 Arbroath and Broughty Ferry SNP SNP (Lara Bird) 31.35%
26 Feb 2026 Gorton and Denton Labour Green (Hannah Spencer) 47.5%
1 May 2025 Runcorn and Helsby Labour Reform UK (Sarah Pochin) 46.2%

Frequently asked

How are UK by-elections triggered?

A by-election is held to fill a vacant seat in the House of Commons. Vacancies arise when an MP dies, resigns, is disqualified, or is expelled. The Speaker issues the writ for the by-election, usually within three months of the vacancy.

How does PollCheck forecast by-elections?

PollCheck combines national and regional polling, the constituency's 2024 General Election result, ward-level demographics, and constituency-specific polling where available, alongside typical mid-term swing patterns.

GB polling 2026 local elections Council control map Path to No10