Frequently Asked Questions — Belfast South Constituency

Who won the Belfast South constituency election in 2019?

Social Democratic and Labour Party gained Belfast South constituency at the 12 December 2019 General Election, taking the seat from Democratic Unionist Party. Social Democratic and Labour Party won with a majority of 15,401 votes (32.5%). Turnout was 67.7%.

What was the swing in Belfast South at the 2019 election?

The swing in Belfast South was 18.6% from DUP to SDLP — a modest shift towards SDLP. Swing is calculated using the Butler two-party formula: the average of the change in winner's vote share and the fall in the runner-up's vote share compared to the previous election here.

What does swing mean in UK elections?

Swing measures how much support has shifted between two parties compared to a previous election. The Butler swing formula — used in British election reporting since the 1950s — takes the average of the gain in the winner's vote share and the loss in the runner-up's. A 5% swing is considered large at ward level; anything above 10% is exceptional. The swing figure for Belfast South in 2019 is shown in the statistics above.