Margin of Error: The Polls

  • Philip Cowley
  • Dennis Kavanagh


The 2015 general election was the most polled in the history of British elections.1 The story the polls told over the final year of the Parliament was essentially one of stability, albeit with a slight Labour decline, and with virtually all polls pointing to deadlock between Labour and the Conservatives. Of over 1,000 polls conducted in the three years after the 2012 Budget, only one had placed the Conservatives above the 37.8% they achieved in May 2015. Of the 92 polls reporting during the six-week campaign, 33 reported a Conservative lead, 41 a Labour lead and 18 a dead heat. Virtually all the leads were within the margin of error inherent in polling.2 Of the 28 polls conducted in the final week, 9 had a Conservative lead, 9 a Labour lead and 10 a tie.


Vote Share Final Poll Polling Company Exit Poll Public Poll 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© The Editor(s) 2016

Authors and Affiliations

  • Philip Cowley
    • 1
  • Dennis Kavanagh
    • 2
  1. 1.Queen Mary University of LondonUK
  2. 2.University of LiverpoolUK

Personalised recommendations