General election forecast
Southampton Test
Predicted winner: Reform UK with 28.1% of the vote, a 0.3pp margin over Labour.
Predicted vote share
How the model expects this constituency to vote
Coloured number is the swing from the 2024 general election result.
Sitting MP
Satvir Kaur
- Party: Labour Party
- Tenure: 1.9 years (since 2024-07-04)
- Status: standing again
See also: TheyWorkForYou
2024 general election result
What happened on 4 July 2024
| Candidate | Party | Votes | Share |
|---|---|---|---|
| Satvir Kaur | Labour Party | 15,945 | 44.5% |
| Ben Burcombe-Filer | Conservative and Unionist Party | 6,612 | 18.5% |
| John Peter Edwards | Reform UK | 5,261 | 14.7% |
| Katherine Jane Barbour | Green Party | 3,594 | 10.0% |
| Thomas Gravatt | Lib Dem | 3,252 | 9.1% |
| Wajahat Shaukat | Workers Party | 775 | 2.2% |
| Maggie Fricker | Trade Unionist and Socialist Coalition | 366 | 1.0% |
Source: Returning officer declaration
How accurate is the model here?
Our 2024 backtest for this constituency
We replayed the same model architecture against the 4 July 2024 general election using only the data a forecaster running the model in May 2024 would have known. Here's what it would have predicted for Southampton Test, and what actually happened.
Predicted
Actual on 4 July 2024
Positive gap = we predicted that party would win more share than they did. See the full GE backtest across all 650 seats for the model's national accuracy.
How this forecast was built
- GE2024 Baseline. Actual GE2024 result in Southampton Test
- National Swing (Strong Transition Model). Multiplicative bounded swing, losers shed in proportion to local share, gainers absorb pro-rata national gain. Replaces additive UNS.
- BES MRP Prior. Baseline blended with BES Wave 1-30 south_east prior at weight 5%
- English-identity floor. English 24.5% → Reform +1.0pp
- Normalise. Shares scaled to 100%