Portsmouth South
South East · Borough constituency · Portsmouth borough
About the Portsmouth South constituency
Portsmouth South is a borough constituency in the South East, covering most or all of Portsmouth. The sitting MP is Stephen Morgan (Labour), first elected in June 2017.
At the 2024 general election, Labour won Portsmouth South with 48.4% of the vote, ahead of Reform UK on 14.7%, a majority of 13,155 votes. Turnout was 52.8%.
If a general election were held today, PollCheck's projection at the current seven-poll average has Labour on 31.4% and Reform UK on 27.5% in Portsmouth South, a margin of 3.9 points. The projection updates automatically as new polls are added.
Demographically, Portsmouth South is closely divided in the 2016 EU referendum (an estimated 51.8% voted Leave in 2016). About 33.0% of residents hold a degree, 41.9% of homes are owner-occupied, and the seat has a median age of about 33 (2021 Census).
Across the last 5 general elections on record, the seat has been won by Labour 3 times, the Liberal Democrats 1 time, the Conservatives 1 time (earlier years may be on predecessor boundaries).
Who lives in Portsmouth South? Constituency demographics
From the 2021 Census and 2016 EU referendum estimates. Constituency-level data on 2024 boundaries.
How did Portsmouth South 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 Portsmouth South
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.
Portsmouth South within Portsmouth
The Westminster constituency of Portsmouth South sits entirely within Portsmouth 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 |
|---|---|---|
| Portsmouth | 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 Portsmouth South at each of the last 60 GB polls. Hover the chart for the underlying poll details.
Who has won Portsmouth South 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 | LD hold | Mike Hancock | 13.7% | 33.3% | 45.9% | 5,200 | 58.7% |
| 2015 | Con gain from LD | Flick Drummond | 19.5% | 34.8% | 22.3% | 5,241 | 58.5%-0.2 |
| 2017 | Lab gain from Con | Stephen Morgan | 41.0% | 37.6% | 17.3% | 1,554 | 63.9%+5.4 |
| 2019notional | Labour winner | Stephen Morgan 2019 MP, pre-review boundary | 48.6% | 37.3% | 11.4% | 5,363 | 63.9%+0.0 |
| 2024 | Lab hold | Stephen Morgan | 48.4% | 14.5% | 12.6% | 13,155 | 52.8%-11.1 |
Earlier years are on pre-2024 boundaries; comparable results on the new boundary will be added when sourced.
Constituencies most like Portsmouth South
Five seats with similar demographic profiles to Portsmouth South. Politics shown for context.
- ↓Owner-occupied41.9 / 44.2vs 61.9
- ↑Private rent36.4 / 33.2vs 20.2
- ↑Under 3544.5 / 40.6vs 30.2
- ↓Owner-occupied41.9 / 45.1vs 61.9
- ↑Private rent36.4 / 34.9vs 20.2
- ↑Under 3544.5 / 41.2vs 30.2
- ↓Owner-occupied41.9 / 35.1vs 61.9
- ↑Private rent36.4 / 36.4vs 20.2
- ↑Under 3544.5 / 49.2vs 30.2
- ↓Owner-occupied41.9 / 43.3vs 61.9
- ↑Under 3544.5 / 42.4vs 30.2
- ↑Private rent36.4 / 28.4vs 20.2
- ↑Under 3544.5 / 47.7vs 30.2
- ↑Private rent36.4 / 33.2vs 20.2
- ↓Owner-occupied41.9 / 51.6vs 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.
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