UK PARLIAMENTARY BY-ELECTIONS · UPDATED 14 SEPT 2026
UK by-elections: upcoming contests, forecasts and results
Follow the next parliamentary contests, confirmed dates and candidates, a transparent polling-based baseline, and every result in the current Parliament.
Official status on the left. A polling-based general-election baseline for the seat on the right.
Date8 Oct 2026
Vacancy
Resignation of Sir Keir Starmer
Vacant since
1 Sept 2026
Previous party
Labour
Candidate watch
Zack PolanskiGreen Party · SelectedSelected by local Green Party members on 10 September; the party announced his candidacy on 11 September. The final ballot is subject to the returning officer's nomination process.
Sagal Abdi-WaliLabour · SelectedLabour's selected candidate attended the party's campaign launch on 12 September. The final ballot is subject to the returning officer's nomination process.
Hussain ShafieiWorkers Party of Britain · Selection reportedThe Standard reported his selection on 8 September. The final ballot is subject to the returning officer's nomination process.
Barmy BrunchOfficial Monster Raving Loony Party · Candidacy announcedThe party's Holborn and St Pancras announcement carries a campaign poster naming Barmy Brunch. The final ballot is subject to the returning officer's nomination process.
On this baseline, Labour leads the 2024 independent baseline. No constituency voting-intention poll has been published for this contest.
The polling-based baseline applies the latest seven-poll Great Britain average uniformly to the 2024 constituency result. It is a general-election scenario, not a constituency poll or a by-election prediction. Local candidates, turnout and tactical voting can produce a very different result. “Other” retains the 2024 independent vote as a baseline and does not represent a confirmed candidate.
Vote shares, turnout and source-led analysis for every completed Westminster by-election since the 2024 general election.
UK parliamentary by-election results since the 2024 general election
Date and seat
Winner
Top two
Turnout
Was it a surprise?
What it tells us
ClactonEngland · Reform UK hold
REFNigel Farage12,784 majority
REF63.3%+17.1
OTH26.9%
44.0%turnout
Expected
The mainstream parties did not stand, leaving Farage overwhelmingly likely to regain the seat he had resigned.
The 63% share looks emphatic, but the unusual field makes this a poor guide to a normal general-election contest. The more useful signal is that over a quarter backed a protest candidate.
Labour was expected to be competitive with Burnham as candidate; winning by more than 20 points made the hold much more decisive.
A high-profile candidate can still rebuild Labour's coalition in a Reform-facing northern seat. Reform's 34.5% confirms its strength, but also shows a ceiling when Labour consolidates its vote.
Aberdeen SouthScotland · Conservative gain from SNP
CONDouglas Lumsden6,050 majority
CON49.5%+25.1
SNP28.6%−4.2
38.0%turnout
Surprise gain
The Conservatives overturned an SNP majority and increased their vote share by 25 points, winning by a margin few national polls would have implied.
The result is a reminder that Scotland does not move in lockstep with GB polling. A concentrated anti-SNP vote and strong local candidate can still produce a large Conservative win.
The SNP entered as the incumbent and converted a narrow 2024 win into a comfortable hold in a low-turnout contest.
Reform rose sharply but finished just behind the Conservatives. The split on the right helped the SNP widen its lead, showing how fragmented opposition can protect an incumbent.
The Greens gained a long-held Labour seat with a 27-point rise while Labour fell from first to third.
Labour can be squeezed from both directions in the same seat. The Greens consolidated progressive voters while Reform took much of the anti-establishment vote.
Runcorn & HelsbyEngland · Reform UK gain from Labour
REFSarah Pochin6 majority
REF38.7%+20.5
LAB38.7%−14.3
46.2%turnout
Major surprise
Reform overturned Labour's large 2024 majority and won by only six votes after a recount.
The result proved Reform could convert national support into a Westminster gain. The six-vote margin also warns against reading a single knife-edge contest as a settled realignment.
Result figures come from UK Parliament or the relevant returning officer. Expected-versus-surprise labels and trend notes are Road to 326 editorial judgements, based on the previous result, vote-share movement and the circumstances of each contest; they are not probabilities or official classifications.
A parliamentary by-election chooses a new MP for one House of Commons constituency when its seat becomes vacant between general elections. It does not reopen every seat or elect a new government.
Why is a by-election held?
A Commons seat can become vacant when an MP resigns, dies, is recalled, becomes ineligible or receives a qualifying criminal sentence. Changing political party does not automatically trigger a by-election.
How long does a UK by-election take?
After Parliament issues the writ, the statutory election timetable normally runs for 21 to 27 working days. The political process before the writ is moved can take longer.
Why do by-election results matter?
A by-election changes one MP, but it can reveal local campaign strength, protest voting and changes in party support between general elections. Turnout and unusual local circumstances mean it should not be treated as a national poll.
Does this page include council by-elections?
No. This tracker covers UK parliamentary by-elections for seats in the House of Commons. Local council, mayoral and devolved-election contests follow separate rules.
UK By-Elections 2026: Upcoming Contests, Forecasts & Results | Road to 326