Ipsos MORI's monthly poll
MORI's monthly political monitor has topline figures, with changes from last month, of CON 42%(-6), LAB 32%(+4), LDEM 14%(-3).
On the surface of it, a huge swing back towards Labour. As a caveat though, the previous MORI poll seemed rather out of line with others - showing the Conservatives way up on 48% when other companies had them in the low 40s - while in terms of the Conservative and Labour position this one is very much in line with other companies figures.
(Incidentally, I don't think the tables for this are up on MORI's website yet, but there is an interesting presentation on voting in the London mayoral election last year, suggesting that voting behaviour correlated more strongly with race than it did social class). I expect this is actually a correction after an outlier, but we shall see - as readers will know, I do always urge caution with any poll showing a large shift of support.
UPDATE: Full results here. Mike Smithson over at politicalbetting argues that the difference is probably largely down to likelihood to vote. MORI's figures without any filtering for likelihood to vote show a much smaller change: CON 39% (nc): LAB 33% (+2): LD 17% (-2). He's probably right. Unlike Populus, ICM and ComRes who weight by people's turnout to vote, so people who say they are 9/10 likely to vote count slightly less than people who are 10/10, but slightly more than people who are 8/10, MORI apply a harsh filter entirely exclusing everyone who doesn't say 10/10. A small firming a party's vote could therefore have a sharp effect on the topline figures - there's a much more detailled explanation of how pollsters take account of likelihood to vote here.
Also interesting is that, like the Sunday Times YouGov poll at the weekend, David Cameron's ratings have shop upwards, giving him a net approval rating of plus 22, equalling the highest MORI have ever found for him. As I said in reference to the YouGov poll, some of this will probably be an expression of sympathy given his recent family tragedy.
Finally, the proportion of people who are optimistic about the economy improving in the next 12 months has also gone back up again. To some extent I suppose it matches up with the post I made at the end of last year about Labour's fortunes being linked with economic confidence (for the record, the TNS data I used in that post also showed people a little more optimistic last month, though not nearly to the extent MORI found). To be honest, I didn't actually expect the correlation to persist, I expected Labour support to drop with economic confidence, but not that it would necessarily rise if confidence returned - government's don't always get credit for these things, and recovery can even make people less risk adverse and more open to alternative government. Still, worth keeping an eye on it.