Local council · Cambridge
Castle
1 seat contested on Thursday 7 May 2026. 6 candidates from 6 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 Castle
| Party | Predicted | Actual | Gap |
|---|---|---|---|
| Reform UK | 15.5% | 4.9% | +10.6pp |
| Labour | 30.3% | 25.5% | +4.9pp |
| Conservative | 6.9% | 3.6% | +3.3pp |
Positive gap = we predicted that party would win more share than they did. See the full Cambridge accuracy summary or the national audit.
Recent contests
What happened last time
| Date | Type | Winner | Top share | Source |
|---|---|---|---|---|
| 2024-05-02 | Cycle | Labour Party | 40.0% | declaration |
| 2023-05-04 | Cycle | Lib Dem | 19.8% | declaration |
| 2022-05-05 | Cycle | Labour Party | 41.8% | declaration |
| 2021-05-06 | Cycle | Labour Party | 13.9% | declaration |
| 2019-05-02 | Cycle | Lib Dem | 49.9% | declaration |
Candidates 2026
Parties on the ballot
- Conservative and Unionist Party
- Green Party
- Independent
- Labour Party
- Lib Dem
- Reform UK
How this area looks demographically
Figures are for Cambridge 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): 47.7% (Census 2021: 53.0%)
- Asian heritage (projected May 2026): 16.1% (Census 2021: 14.8%)
- Average area deprivation decile: 6.6 (1 = most deprived, 10 = least)
How this prediction was made
- Baseline . Most recent borough result (2024-05-02)
- BES MRP Prior . Baseline blended with BES Wave 1-30 east_of_england prior (weight 15%, n=3761 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 estimated at 17.8% from GE/LCC proxy + swing
- Normalise . All shares scaled to sum to 100%
- Restrict to ballot . Removed 3 party/parties not standing in 2026 (SNP 0.1pp, Other 0.0pp, Plaid Cymru 0.0pp). Their share redistributed pro-rata.
- 2025 county-cycle anchor . Blended (weight 0.1) toward May 2025 results for cambridgeshire (59 divisions, 185,747 votes), adjusted by national swing since May 2025. This corrects the model's tendency to under-weight Reform's 2025 county breakthroughs in 2-tier districts.
- 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.