Opinion polling in United Kingdom constituencies (2010–2015)
Prior to the 2015 general election, various polling organisations conducted opinion polling in specific constituencies. The results of publicised opinion polling for individual constituencies are detailed in this article. However, most opinion polling covers Great Britain, where the results are published in this article here.
Opinion polls were conducted gradually from the months after the previous general election held on 6 May 2010, and increased in frequency before the general election which took place on 7 May 2015. Though most opinion polls published are for general election voting intention, some polls shown are for voting intention in separate by-elections.
Polls of individual constituencies are expensive compared to national polling and were previously an infrequent practice in the UK. However, a large number of individual constituency polls were carried out in this period, most commissioned from independent polling providers by Michael Ashcroft, a Conservative peer and sponsor. In addition to polls listed in this article, other polling of constituencies has been carried out in private, often by political parties.[1]
Given the expense of polling individual constituencies, constituencies are usually only polled if they are of some particular interest, e.g. they are thought to be marginal or facing an impending by-election. The constituencies polled are not necessarily representative of a national average swing. Under the first-past-the-post electoral system true marginal seats are, by definition, decisive as to the election outcome.[2]
1: These figures represent the results when respondents were presented with named candidates. When asked to think only about the political parties [the methodology used by the Ashcroft polls] the figures showed a small Labour lead.[4]
Some polls are carried out in specified subsets of marginal constituencies. Most of the polls for Michael Ashcroft were compilations of polls in individual constituencies.
The Lord Ashcroft polls typically ask two voting intention questions, with the second question asking the respondent to think "specifically about your own constituency and the candidates who are likely to stand there".[2] This latter question is reported in the tables above.
Most polling companies are members of the British Polling Council and abide by its disclosure rules; however, Michael Ashcroft, who commissioned many of these polls, is not a BPC member, despite having been invited to join. However, he contracts the conduct of his polls to BPC members.[5]