Portsmouth South.

Portsmouth South is among the most compact seats in the country, contained entirely within the city of Portsmouth and its dense island geography. With a population of roughly 117,000 and a median age of 33, it is young and notably urban, more so than most South East seats, and around a third of residents hold a degree. There is no patchwork of towns here: the whole constituency sits within a single built-up area. Local services are run by Portsmouth City Council, a unitary authority, which administers the seven wards that make up the seat.

That single council is where the recent movement has been. Across the seven most-recent ward contests, held in May 2026, the Liberal Democrats took six -- Central Southsea, Eastney and Craneswater, Fratton, Milton, St Jude and St Thomas -- while Reform UK carried Charles Dickens. Turnouts ran broadly even across the wards, in the three-to-five-thousand range. The parliamentary picture diverges from this local pattern: at the 2024 general election Labour won the seat on 48.4 per cent, with Reform UK a distant runner-up on 14.7. Stephen Morgan, Labour's MP since 2017, holds that Westminster seat against a council map his party no longer leads.

The direction of travel at local level appears firmly Liberal Democrat, and recent coverage has tended to track that consolidation of control rather than any contest over it. Labour's strength remains a Westminster phenomenon, sitting atop a city administration where its position has thinned. Several categories of recorded crime run well above the constituency average, among them violence and sexual offences, shoplifting and public order offences, as one might expect of a densely populated city seat. The result is a constituency that looks settled for Labour at the parliamentary level while its local politics moves elsewhere -- held, but no longer aligned top to bottom.