As we enter the closing stretch of the campaign, substantial uncertainty remains about the final outcome. Taking out the random noise, the polls are still showing a close race ahead of May 7th. Some have pointed to differences between telephone and internet pollsters, with the former having shown a steady, if slight, Conservative lead all year. Our method allows us to control for systematic differences between polling houses and variation in the ‘poll of polls’ that is due to changes in the mix of pollsters in the field at a given point in time.
The final Polling Observatory forecast covers all polls completed up until April 30th, and shows support for the two main parties is still in the balance – with Labour on 33.1% and the Conservatives on 34.2% -- though the confidence intervals are such that we cannot say for certain that the Conservative lead is greater than zero.