Frequently Asked Questions — Don Valley Constituency

Who won the Don Valley constituency election in 2015?

Labour gained Don Valley constituency at the 7 May 2015 General Election, taking the seat from Conservative. Labour won with a majority of 8,885 votes (20.9%). Turnout was 59.6%.

What was the swing in Don Valley at the 2015 election?

The swing in Don Valley was 14.4% from CON to LAB — a modest shift towards LAB. 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 Don Valley in 2015 is shown in the statistics above.