Today’s YouGov poll has topline figures of CON 36%(-2), LAB 32%(+1), LDEM 20%(+1). The Tory lead is back down to four points (in fact the figures are the same as YouGov were showing on Wednesday and Thursday last week) and it looks very likely that the 7 point lead YouGov recorded over the weekend was just a result of sample error. Clearly there is no sign of the current lobbying row having damaged Labour yet.
This poll actually makes rather more sense to me than the YouGov and ICM polls that were showing the same figures over the weekend. For the last month or so ICM have tended to show Conservative leads a couple of points higher than YouGov’s, so while nothing to write home about (after all, all polls are subject to margin of error) it was rather unusual to find ICM showing a 6 point when YouGov were on 7. With ICM on six points, I’d expect to find YouGov on four.
While it’s normally impossible to precisely identify the reasons for differences between polls (there are so many different variables: the mode, the sampling, the wording, the weighting, etc) one obvious explanation is likelihood to vote – ICM weight people by how likely they are to vote, YouGov do not.