Mitcham and Morden
London · Borough constituency · Merton borough
About the Mitcham and Morden constituency
Mitcham and Morden is a borough constituency in London, covering most or all of Merton. The sitting MP is Dame Siobhain McDonagh (Labour), first elected in May 1997.
At the 2024 general election, Labour won Mitcham and Morden with 55.4% of the vote, ahead of the Conservatives on 14.0%, a majority of 18,761 votes. Turnout was 58.6%.
If a general election were held today, PollCheck's projection at the current seven-poll average has Labour on 40.1% and Reform UK on 19.0% in Mitcham and Morden, a margin of 21.1 points. The projection updates automatically as new polls are added.
Demographically, Mitcham and Morden is a Remain-leaning area (an estimated 44.7% voted Leave in 2016). About 40.0% of residents hold a degree, 53.1% of homes are owner-occupied, and the seat has a median age of about 37 (2021 Census).
Across the most recent general elections on record here, the seat has been won by Labour each time.
Who lives in Mitcham and Morden? Constituency demographics
From the 2021 Census and 2016 EU referendum estimates. Constituency-level data on 2024 boundaries.
How did Mitcham and Morden vote in 2024 and how would it vote now?
2024 vote shares from the HoC Library. Current projection is at the 7-poll average.
2024 general election
Current projection
Map of Mitcham and Morden
Switch between ward-level 2024 election winners and a demographic view. Ward winners are Britain Elects' / New Statesman modelled estimates with an average ~4pp margin of error per ward. The demographic view splits the seat into small neighbourhoods (around 1,500 residents each, from the 2021 Census). Hover any area for detail.
Mitcham and Morden within Merton
The Westminster constituency of Mitcham and Morden sits entirely within Merton Council. Local council elections are a separate ballot from Westminster general elections - the figures below are from the council elections held on Thursday 7 May 2026.
Council overlap
| Council | Share of seat | Projection |
|---|---|---|
| Merton | 100% | View projection › |
Most recent council ward results
Latest council winner per ward. Where the council held a May 2026 election, those results are shown; otherwise we show the most recent available ward result (via DCLEAPIL, 2014-2024), or, where the seat was uncontested at the last election, the current sitting councillor from OpenCouncilData. The "Shift since GE2024" column is only computed for May 2026 results - earlier council votes pre-date the GE, so no directional shift is shown.
| Ward | GE2024 winner | Latest council winner | Shift since GE2024 | Turnout |
|---|
Projection trajectory
PollCheck's projection for Mitcham and Morden at each of the last 60 GB polls. Hover the chart for the underlying poll details.
Who has won Mitcham and Morden at past general elections?
2024 result is on current boundaries. The 2019 row is the UK Parliament's notional recalculation onto the 2024 boundaries (directly comparable to 2024). The 2010, 2015 and 2017 rows are on the boundaries in force at the time and aren't directly comparable.
| Year | Result | MP | Lab | Con | LD | Majority | Turnout |
|---|---|---|---|---|---|---|---|
| 2010 | Lab hold | Siobhain McDonagh | 56.4% | 25.2% | 11.9% | 13,666 | 66.4% |
| 2015 | Lab hold | Siobhain McDonagh | 60.7% | 23.2% | 3.1% | 16,922 | 65.9%-0.5 |
| 2017 | Lab hold | Siobhain McDonagh | 68.7% | 24.2% | 3.1% | 21,375 | 70.0%+4.1 |
| 2019notional | Labour winner | Siobhain McDonagh 2019 MP, pre-review boundary | 57.5% | 26.7% | 10.8% | 15,879 | 67.2%-2.8 |
| 2024 | Lab hold | Siobhain McDonagh | 55.4% | 14.0% | 8.0% | 18,761 | 58.6%-8.6 |
Earlier years are on pre-2024 boundaries; comparable results on the new boundary will be added when sourced.
Constituencies most like Mitcham and Morden
Five seats with similar demographic profiles to Mitcham and Morden. Politics shown for context.
- ↓Owner-occupied53.1 / 49.9vs 61.9
- ↓Age 65+14.6 / 15.4vs 22.7
- ↑Private rent27.0 / 28.3vs 20.2
- ↑Private rent27.0 / 27.4vs 20.2
- ↓Age 65+14.6 / 15.8vs 22.7
- ↑Graduate40.0 / 41.1vs 33.7
- ↓Age 65+14.6 / 13.3vs 22.7
- ↓Owner-occupied53.1 / 48.2vs 61.9
- ↓Leave44.7 / 34.8vs 53.2
- ↓Owner-occupied53.1 / 50.3vs 61.9
- ↓Leave44.7 / 41.5vs 53.2
- ↑Graduate40.0 / 39.4vs 33.7
- ↓Age 65+14.6 / 14.2vs 22.7
- ↓Leave44.7 / 41.6vs 53.2
- ↓Owner-occupied53.1 / 44.3vs 61.9
What would change this seat?
Move the sliders to set national vote shares. The per-seat projection updates live. Reset returns to the current 7-poll average.
Related
Sources
- 2024 general election results · UK Parliament Election Results portal and House of Commons Library briefing CBP-10009.
- Notional 2019 results on 2024 boundaries · UK Parliament Election Results portal. Recalculated by Parliament; carries assumptions about how 2019 voters would have distributed across the redrawn boundaries.
- Historic general election results (2010-2017) · House of Commons Library historic results files (on the boundaries in force at the time).
- Ward-level GE2024 estimates · Britain Elects / New Statesman - article by Ben Walker, underlying spreadsheet. Modelled from constituency totals; average ~4pp per-ward MoE.
- May 2026 council ward results · Democracy Club via PollCheck's locals 2026 dataset.
- Earlier council ward results (2014-2024) · DCLEAPIL v1.0 (Jason Leman, drawing on Andrew Teale's LEAP dataset and Democracy Club).
- Demographics · ONS Census 2021 (England and Wales), aggregated to constituency level using the ONS LSOA21 -> PCON24 best-fit lookup.
- EU referendum 2016 estimates · Constituency-level Leave vote estimates (Hanretty 2017 method).
- MP details and Cabinet roles · UK Parliament Members API. MP photos are fetched live from the same source.
- Boundary geometry and lookups · ONS Open Geography Portal (PCON24 boundaries, LSOA21 boundaries, LSOA21-WD24-LAD24 best-fit lookup).
- Current projection and trajectory · PollCheck's demographic swingometer applied to the rolling 7-poll average from aggregated GB polls. Not a true MRP - vote-share movements are applied through per-constituency sensitivity multipliers derived from demographic regressions.
If you spot a data issue, please let us know.