Try our new Electoral Reform tool
Westminster Polling Error Analysis
Click the button below to run 1000 simulations of a Westminster general election using randomised vote shares centred around the current polling average. It then applies a further layer of variation by tweaking every party's swing in every constituency based on local factors, including region, urban/rural classification, and more.
We use the Monte Carlo method to demonstrate the degree of uncertainty that's inevitable in election projections and show how even small polling errors, and local factors can lead to significantly different outcomes. In many cases the difference between an excellent year for a party and a terrible year is well within a normal polling error.
Click the button below to run the analysis. Results are calculated using the latest polling data.
The same analysis for Scotland, Wales, and Northern Ireland is also available.
Seat Projection Over Time
Each party's mean projected seats from 1,000 Monte Carlo simulations of the nowcast, updated daily. The darker shading covers 50% of the distribution, and the lighter shading extends to 95%. Large jumps/drops in the average number of seats is usually linked to the addition of a new poll to our database.
Hover over a party's line or name to show its range. Click to keep it shown.
Current Polling Average
England
Scotland
Wales
Northern Ireland
Each nation's parties are shown as a share of that nation's own vote -- England, Scotland, Wales and Northern Ireland are simulated independently, same as the Nowcast preset on Westminster.