UK Decides draws on original polling releases, official election results, parliamentary records and published statistical data. This page identifies the main sources behind our polling, constituency, election and research coverage, and explains how we use them.
Opinion polls and pollsters
Our polling database records Westminster voting-intention surveys, with fieldwork dates, sample details and links to original releases wherever available. The Poll of Polls draws on those records; its inclusion rules are explained alongside the figures.
Polling organisations represented in our database include YouGov, Opinium, More in Common, Survation, Ipsos, Find Out Now, BMG Research, Deltapoll, Focaldata, JL Partners, Freshwater Strategy, Techne UK, Trajectory and Verian.
See our UK polling companies directory for the pollsters currently represented, their latest recorded polls and links to their websites. Inclusion is not an endorsement or a rating of a polling company’s accuracy.
The British Polling Council publishes disclosure standards and information on member organisations. Where possible, we check an individual poll against the pollster’s original publication and data tables rather than relying solely on press coverage. Our methodology explains how UK Decides selects and presents polling data.
Parliament and constituency information
The UK Parliament Developer Hub supplies public APIs for MPs and parliamentary information. Parliament’s published records also provide a basis for constituency and election coverage.
The House of Commons Library publishes election results, constituency material and research briefings. We use these alongside primary election records where appropriate, keeping the date and constituency boundaries of each dataset clear.
Official election results and electoral information
The Electoral Commission provides information on elections, electoral law, political finance and official guidance. For election results, the relevant returning officer’s or council’s published declaration is an important primary record; national compilations can make those results easier to compare.
Our elections coverage and constituency pages distinguish recorded election results from polling or modelled estimates.
Statistics, population and boundaries
The Office for National Statistics provides population, census and other statistical data for England and Wales. We also refer, where relevant, to National Records of Scotland, the Northern Ireland Statistics and Research Agency and official boundary information.
Comparisons need to use the correct geography and reference year: a historical constituency result or census figure should not be presented as if it describes today’s boundaries or population.
How we use and correct sources
UK Decides aims to link readers to the original evidence, whether that’s a pollster’s release, a declaration of election results or an official statistical publication. Secondary reporting may provide useful context but does not replace an available primary record.
We identify fieldwork dates rather than treating a poll’s publication date as the date opinion was measured, and distinguish observed results from calculated averages, projections and other analytical estimates. See our editorial standards and methodology for further details.
If a source is missing, superseded or incorrectly represented, please email info@ukdecides.com. We welcome corrections and suggestions for additional original datasets.