A YouGov poll in today's Sunday Times gives Dave Cameron's Conservatives their biggest lead over Labour since 1992. The poll puts the Conservatives on 44 per cent, Labour on 28 per cent and the Liberal Democrats on 17 per cent.
It does sometimes seem that YouGov gives the Conservatives a bigger lead than other polls. Of course, they are a reputable organisation using an innovative method that has allowed them to recruit a very large panel. However, even today, not everyone is on the internet.
Of course, YouGov can constitute their samples to take account of population demographics on a range of criteria. Nevertheless, supposing we take a group like less well off people over 60. No doubt YouGov has been able to recruit sufficient numbers to their panel. But are, say, DEs over 60 who are connected to the internet typical of all DEs over 60? Their demographic characteristics, including their income range, may be similar but might they differ on more subtle factors? I don't know, but it would be interesting to learn more.
There is not going to be an election tomorrow, so these figures should not be treated as indicative of a result in 2009 or 2010. What I find the most interesting figure is that only 11 per cent of those questioned think Labour will win the general election. This is often a rather good predictor of what might happen in a general election.
Some commentary by YouGov on their London mayoral results can be found here, although it does not address the sampling issue: