Local council · Lambeth

Streatham St Leonard's

3 seats contested on Thursday 7 May 2026. 15 candidates from 5 parties.

Confidence in the forecast: Medium · Official Statement of Persons Nominated (PDF)

Ward locator for Streatham St Leonard's; neighbouring wards shaded by Reform UK vote-share difference vs this ward.

Neighbours shaded by Reform UK share vs this ward, red = higher, blue = lower.

Predicted vote share

What the model expects

Green Party
32.9%
Reform UK
31.6%
Labour
21.4%
Conservative
7.3%
Lib Dem
6.7%

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 Streatham St Leonard's

✓ Winner called correctly , predicted Green Party, actual Green Party. Major-party MAE: 5.76pp across the parties below.
PartyPredictedActualGap
Reform UK 21.6% 7.2% +14.4pp
Labour 22.5% 23.7% -1.2pp
Conservative 8.1% 8.1% +0.0pp

Positive gap = we predicted that party would win more share than they did. See the full Lambeth accuracy summary or the national audit.

Recent contests

What happened last time

DateTypeWinnerTop shareSource
2022-05-05 Cycle Green Party 16.2% declaration

Candidates 2026

Parties on the ballot

View the official Statement of Persons Nominated (PDF)

How this area looks demographically

Figures are for Lambeth 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.

How this prediction was made
  1. Baseline . Most recent borough result (2022-05-05)
  2. BES MRP Prior . Baseline blended with BES Wave 1-30 london prior (weight 15%, n=3660 regional respondents)
  3. National Swing (STM) . Strong Transition Model: multiplicative bounded swing, dampened by 0.65 for local
  4. Demographics . 1 demographic factor(s) applied
  5. Incumbency . No current holder data available
  6. New Party Entry . Reform UK estimated at 12.8% from GE/LCC proxy + swing
  7. Normalise . All shares scaled to sum to 100%
  8. Restrict to ballot . Removed 3 party/parties not standing in 2026 (SNP 0.3pp, Plaid Cymru 0.1pp, Other 0.0pp). Their share redistributed pro-rata.
  9. 2025 county-cycle anchor . No 2025 reference available for this council's parent area. Stage 1 uses national polling only.
  10. 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.

Read the full local-elections methodology →

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