Frequently Asked Questions — Belfast South Constituency

Who won the Belfast South constituency election in 2017?

Democratic Unionist Party gained Belfast South constituency at the 8 June 2017 General Election, taking the seat from Social Democratic and Labour Party. Democratic Unionist Party won with a majority of 1,996 votes (4.6%). Turnout was 66.1%.

What was the swing in Belfast South at the 2017 election?

The swing in Belfast South was 18.6% from SDLP to DUP — a modest shift towards DUP. 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 2017 is shown in the statistics above.