Prior to the 2015 United Kingdom 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 Lord 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. 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. Constituency polls England Amber Valley Bedford Bermondsey and Old Southwark Berwick-upon-Tweed Birmingham Edgbaston Birmingham Yardley Blackpool North and Cleveleys Bognor Regis and Littlehampton Bolton West Boston and Skegness Bradford East Brent Central Brentford and Isleworth Brighton Kemptown Brighton Pavilion Bristol North West Bristol West Broxtowe Burnley Bury North Camborne and Redruth Cambridge Cannock Chase Carlisle Carshalton and Wallington Castle Point Cheadle Cheltenham Chippenham City of Chester Clacton Cleethorpes Colchester Colne Valley Corby Crewe and Nantwich Croydon Central Derby North Dewsbury Doncaster North Note: Michael Ashcroft initially published incorrect results for his 18–23 Nov 2014 poll, erroneously showing only a small Labour lead. The corrected poll results are below. Dover Dudley North Dudley South Ealing Central and Acton Eastbourne Eastleigh Elmet and Rothwell Enfield North Erewash Finchley and Golders Green Folkestone and Hythe Gloucester Great Grimsby Great Yarmouth Halesowen and Rowley Regis Halifax Hampstead and Kilburn Harlow Harrogate and Knaresborough Harrow East Hastings and Rye Hazel Grove Hendon Heywood and Middleton High Peak Hornsey and Wood Green Hove Ipswich Keighley Kingston