ICM and YouGov both show 8 point leads
As well as the marginals poll for the News of the World, there is a national ICM poll for the Sunday Telegraph. The topline figures there are CON 38%(+1), LAB 30%(-3), LDEM 21%(nc). The changes are from the ICM poll done over the Easter weekend which showed a 4 point lead, which seemed rather out of line at the time. I suspect the apparent drop in Labour support in this poll therefore is not really meaningful, just a reversion to the mean after an outlier.
Channel Four news have also reported the topline voting intention for YouGov's Sunday Times poll, which according to them shows figures of CON 40%(nc), LAB 32%(+2), LDEM 18%(-2). The Conservatives remain on 40%, but Labour recover from the 30% they showed yesterday. Viewed together ICM, YouGov and ComRes all have pretty consistent figures for the Conservatives (38,39,40) and Labour (30,32,32). There is also supposed to be a BPIX poll tonight in the Mail on Sunday that I've seen quoted as showing a 7 point lead, though I haven't seen any full figures yet.
The 8 point lead in the ICM poll equates to a 5.5% swing, so we can now compare this to the 6.3% swing in the ICM marginals poll earlier and it suggests the Conservatives are only doing very slightly better in marginal seats. To put the level of the "marginals bonus" in context, if the Conservatives need an 11% lead to get an overall majority on a uniform swing, if their swing in marginal seats is 0.8% higher then they would actually get an overall majority with a lead of 9.6%.
Of course, marginal polls have margins of error like any other, so don't take that 0.8% marginals advantage as gospel - it could be larger or smaller than that, all we can be relatively certain about is that the Conservatives do have an advantage in Con-v-Lab marginals (since all polls of marginal seats have shown it), and that it isn't particularly large (since no one has shown it higher than a point or two).
UPDATE: Incidentally, yesterday we had a Harris poll suggesting 65% of people were in favour of supporting marriage by raising allowances for married couples. I said at the time that it was one of those things that depend on how you ask the question, so tonight we see ICM's poll in the Sunday Telegraph finding only 35% supporting it and 65% opposed - the implication is that the question asked about a tax reduction for married couples but not unmarried people - so putting it as a question about fairness rather than supporting marriage.
Which one tells us the true picture? Well, I haven't seen the exact wording of either so I can't really say for certain, but assuming both are fair and balanced questions it's possible they are both right and reflect different ways of looking at it. Which gives us the better guide to how the public will react to the policy would depend on whether the political debate and public perceptions of the policy end up being about fairness, or about support for marriage. It's a reminder that polls do by necessity force public opinion into neat little boxes for media consumption, when public opinion is almost always more complicated and nuanced.
UPDATE 2: Those YouGov figures from Channel 4 earlier are now confirmed. No sign of the BPIX figures yet.
