The Performance of the Polls in the 2019 General Election

After being widely criticised for their performance in the 2015 and 2017 general elections, the polls have proven more accurate in the 2019 election than in any contest since 2005.

As the table shows, on average the final polls underestimated the Conservative vote by just 1.4 points and overestimated Labour’s by only 0.5 points.

These patterns are consistent with the long-term trend for the polls to over-state Labour and under-state Tory support, but the size of the errors were so small that this did not prevent the polls correctly predicting the overall outcome of the election.

For all the other parties, the average error across the pollsters was under one point. Indeed for the LibDems, Greens, and Others the average error was a remarkably small 0.1 of a point.

 CONLABLDBrexitGREENOTHERMETHODSAMPLE SIZEFIELDWORK
Qriously433012348Online2222Dec 5-8
ICM423612324Online2011Dec 6-9
YouGov433412335Online105,612Dec 4-10
Savanta ComRes413612326Online1732Dec 9-10
BMG413214345Online1660Dec 6-11
Ipsos MORI443312236Telephone2213Dec 9-11
Kantar 443213335Online2815Dec 9-11
Deltapoll453510334Online1818Dec 9-11
Survation45349336Telephone2395Dec 10-11
Panelbase433411435Online3174Dec 10-11
Opinium453312226Online3005Dec 10-11
Average43.333.511.72.92.95.5   
Result44.733.011.82.12.85.6   
Difference-1.40.5-0.10.80.1-0.1   

There was also a Survation poll in Scotland conducted online from Dec 10-11 with 1,004 respondents.

pollResult
SNP4345.0
Con2825.1
Lab2018.6
Lib Dem79.5
Other21.7