Local council · Southampton
Shirley
1 seat contested on Thursday 7 May 2026. 5 candidates from 5 parties.
Neighbours shaded by Reform UK share vs this ward, red = higher, blue = lower.
Predicted vote share
What the model expects
Predictions are point estimates: the model's best guess, not a guarantee. The "How this prediction was made" section below lists every step that shaped this forecast.
How accurate was the model here?
Our 7 May 2026 forecast for Shirley
| Party | Predicted | Actual | Gap |
|---|---|---|---|
| Reform UK | 32.7% | 18.4% | +14.4pp |
| Labour | 25.2% | 25.3% | -0.1pp |
| Conservative | 7.6% | 8.8% | -1.3pp |
Positive gap = we predicted that party would win more share than they did. See the full Southampton accuracy summary or the national audit.
Recent contests
What happened last time
| Date | Type | Winner | Top share | Source |
|---|---|---|---|---|
| 2026-02-26 | By-election | Lib Dem | 27.3% | declaration |
| 2024-10-10 | By-election | Lib Dem | 39.2% | declaration |
| 2024-05-02 | Cycle | Labour Party | 39.5% | declaration |
| 2023-05-04 | Cycle | Labour Party | 17.8% | declaration |
| 2022-05-05 | Cycle | Labour Party | 27.8% | declaration |
Candidates 2026
Parties on the ballot
- Conservative and Unionist Party
- Green Party
- Labour Party
- Lib Dem
- Reform UK
How this area looks demographically
Figures are for Southampton as a whole. The same local-authority figures are used for every ward in the council, finer ward-level demographics will land in a future release.
- White British (projected May 2026): 62.4% (Census 2021: 68.1%)
- Asian heritage (projected May 2026): 11.3% (Census 2021: 10.6%)
- Average area deprivation decile: 4.1 (1 = most deprived, 10 = least)
How this prediction was made
- Baseline . Most recent borough result (2026-02-26)
- BES MRP Prior . Baseline blended with BES Wave 1-30 south_east prior (weight 15%, n=5565 regional respondents)
- National Swing (STM) . Strong Transition Model: multiplicative bounded swing, dampened by 0.1 for local
- Demographics . 1 demographic factor(s) applied
- Incumbency . No current holder data available
- New Party Entry . Reform UK has existing baseline, no proxy needed
- Normalise . All shares scaled to sum to 100%
- Restrict to ballot . Removed 5 party/parties not standing in 2026 (Independent 2.9pp, Trade Unionist and Socialist Coalition 0.4pp, SNP 0.0pp, Plaid Cymru 0.0pp, Other 0.0pp). Their share redistributed pro-rata.
- 2025 county-cycle anchor . No 2025 reference available for this council's parent area. Stage 1 uses national polling only.
- Reform realignment uplift (no-anchor councils) . No 2025 parent-county anchor available; demographic-borrow rule applied. Asian 11.3% → base target 32.2% × regional multiplier 0.85 = 27.4%. Reform 18.1% → 27.4% (lift +9.3pp). Other parties scaled pro-rata. Calibration source: Burnley 2026 ward-level Asian%↔Reform% relationship (the 2-tier district that did receive the LCC 2025 anchor).
- National-share calibration . Aggregate-predicted vs national-polled mismatch corrected at strength 0.65. Multipliers — Labour ×0.82, Conservative ×1.00, Reform UK ×1.15, Liberal Democrats ×0.96, Green Party ×1.12, SNP ×1.00, Plaid Cymru ×1.00.