Last year established a new record for the rate at which by-election seats are changing hands.
Each of the final three quarters of the year saw more seats change party control than were held. This level of volatility has only been recorded nine times, and never before over such a long sequence.
Seat turnover in the final quarter reached 62 per cent, matching the previous record set between January-March 1986.
The latest contests further underline Reform UK’s capacity to undermine the established order as the party took seats from Labour, Conservatives, Liberal Democrats, and Independents.
It comfortably defended its own two vacancies, although vote share fell in both. These results push Reform’s total by-election gains to more than 100 since the last general election.
Such momentum explains why Reform leads opposition to any further postponement of council elections, a move that limits its ability to strengthen its local government presence.
Three gains from Labour – in Sunderland, Darlington, and Blackpool – highlight the scale of the challenge facing Labour as next May’s elections approach.
Sunderland’s Hetton ward typically votes Labour, with Reform polling just 11 per cent in 2024. That old pattern changed as Labour’s vote fell by 25 points, while Reform’s rose by 35.
In Darlington’s Red Hall and Lingfield ward, Reform, which had not stood there in 2023, recorded a 38 per cent swing in its favour.
In Blackpool Greenlands, both Labour and the Conservatives were squeezed, with Reform’s vote matching the combined total of the two parties.
Elsewhere, in South Kesteven’s Aveland ward, the Conservatives were unopposed in 2019 and won comfortably in 2023, but were edged out by Reform this time, by just 10 votes.
The Conservatives won both Pakefield seats in Suffolk in 2021 but lost one to Labour at a by-election held on general election day 2024. Reform secured almost half the vote in this second vacancy.
While Reform is taking seats from Labour and the Conservatives, its gains from the Liberal Democrats are fewer.
One such was Middlesbrough’s two-member Nunthorpe ward. Elected as a Liberal Democrat-Conservative split in 2023, the by-election saw Reform squeeze both parties and secure a narrow 13-vote win.
Reform also gained two former Independent seats – Hunstanton in King’s Lynn and West Norfolk, and Belmont in South Kesteven.
The Liberal Democrats recorded two gains from the Conservatives in Devon – Torridge’s Winkleigh ward and Seaton in East Devon. In both cases, the Conservative vote was reduced by Reform’s presence.
Seat exchanges in the opposite direction remain rare. However, the resignation of a Liberal Democrat councillor in Market Harborough’s Logan ward created an opening, which the Conservatives seized with a 20-point swing.
| local by-elections |
|---|
| Blackpool, Greenlands REF GAIN FROM LAB 21.8% over Con Turnout 24.7% |
| Broxtowe, Stapleford South East BROX ALLIANCE GAIN FROM LAB 12.8% over Ref Turnout 28.2% |
| Caerphilly, Penyrheol PLAID CYMRU HELD 33.6% over Ref Turnout 16.3% |
| Cornwall, St Columb Minor and Colan REF HELD 6.4% over Ind Turnout 27.7% |
| Darlington, Red Hall and Lingfield REF GAIN FROM LAB 20.3% over Con Turnout 27.5% |
| Derbyshire, Long Eaton North REF HELD 0.9% over Con Turnout 29.0% |
| East Devon, Exmouth Halsdon LIB DEM HELD 7.4% over Ref Turnout 25.5% |
| East Devon, Seaton LIB DEM GAIN FROM CON 11.7% over Ref Turnout 33.4% |
| Harborough, Logan CON GAIN FROM LIB DEM 19.9% over Lib Dem Turnout 30.5% |
| Kings Lynn & West Norfolk, Hunstanton REF GAIN FROM IND 3.7% over Lib Dem Turnout 33.0% |
| Lichfield, Armitage With Handsacre CON HELD 14.7% over Ref Turnout 22.4% |
| Middlesbrough, Nunthorpe REF GAIN FROM LIB DEM 0.8% over Lib Dem Turnout 35.8% |
| Pendle, Barnoldswick LIB DEM HELD 33.6% over Ref Turnout 25.8% |
| South Kesteven, Aveland REF GAIN FROM CON 1.4% over Con Turnout 35.7% |
| South Kesteven, Belmont REF GAIN FROM IND 0.3% over Con Turnout 20.9% |
| South Ribble, Broad Oak LIB DEM HELD 44.5% over Ref Turnout 35.3% |
| Stockton-On-Tees, Eaglescliffe West CON HELD 36.9% over Ref Turnout 35.8% |
| Suffolk, Pakefield REF GAIN FROM CON 29.7% over Green Turnout 22.6% |
| Sunderland, Hetton REF GAIN FROM LAB 21.2% over Ind Turnout 29.3% |
| Torridge, Winkleigh LIB DEM GAIN FROM CON 9.5% over Ref Turnout 41.8% |
| Watford, Tudor LIB DEM HELD 26.0% over Ref Turnout 30.5% |
- For the full results, and additional data on other local by-election results, please download LGA council results December 2025