Welcome to the Opinium Election Polling Centre.

Opinium produces a fortnightly Opinium/Observer Political Poll with the Observer newspaper as well as work for numerous other organisations and media outlets. Our latest results, as well as the archive of our previous results can be found at the right of this page.

Current voting intention:

Voting Intention Tracker
Please note that from the beginning of February 2015 our polls have used our updated election methodology, details of which can be found here.

Survey methodology:

Interview Method

This survey is conducted online using Opinium’s highly engaged consumer panel of UK adults.


This research is run from a representative sample of adults (aged 18+) in England, Scotland and Wales

Sampling Method

  • The sample is defined from pre-collected registration data containing gender, age (18-34, 35-54, and 55+) and region (North East, North West, Yorkshire and Humberside, East Midlands, West Midlands, East of England, London, South East, South West, Wales, and Scotland) to match the latest published ONS figures
  • The sample variables are defined within our panel management software and then randomised using a purpose built visual basic macro
  • Opinium also takes into account differential response rates from the different demographics groups (e.g. those aged under 35, typically have a response rate of 1/3rd of those aged over 55), to ensure the sample is representative
  • To test the robustness of the sample we have run additional controls, measuring such things as the respondents’ propensity to vote for each major party, their past vote, and confirmed that the results were generally similar to some major mass surveys such as Eurobarometer and the European Elections Study

Data weighting

  • Data is weighted to the profile of all adults aged 18+ (including households without internet access) according to gender, age, region, working status and social class
  • Age, gender and region weighting figures are taken from the published ONS statistics. Social class weighting figures are taken from NRS published figures. Working status weighting figures are derived from a combination of ONS published figures and our own research
  • Targets for party propensity are taken from previous Opinium research and adjusted weekly based on a rolling average of the results of the relevant questions in our regular polling
  • Our weighting matrix has been developed in conjunction with Professor Michael Bruter of the LSE

Voter turnout

All those that state they intend to 'definitely' or 'probably' vote for a specific party are included in the final calculation, and are all treated as equal. This is due to the fact that they aim of this survey is to accurately estimate the current voting intentions of the public, rather than predict the levels of voter turnout. This approach maximises the effective sample size, giving a base of around 1,400 responses for each wave. This sets the margin of error at 2.4% (or better) for a party with a 30% share of vote

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