Interesting thoughts from Peter Kellner:
During election week, YouGov asked people where they placed themselves on the Left, centre or Right. We offered three variations of Left and Right: “very”, “fairly” and “slightly”. At first sight, Labour and Lib Dem supporters look fairly similar, and very different from Conservative supporters. Labour supporters divide: 54% Left, 23% centre and 5% Right, while Lib Dem voters divide: 43%-29%-9%. Contrast those figures with the Tories: 5%-21%-57%. If that were the only evidence we had, then the conclusion would be irresistible: most British voters belong to one of the two tribes on the left bank of British politics, while only a minority belong to the one significant tribe on the right bank.
But that is not the only piece of evidence. When we asked the same Lib Dem voters which they would prefer if they had to choose, 51% plumped for a Labour government led by Gordon Brown, while 36% opted for a Conservative government led by David Cameron. So the advantage resides with Labour, but it is far from overwhelming – and very different from 2005, when Lib Dem voters opted by three-to-one for Labour/Blair over Conservative/Howard.
Among the electorate as a whole, the division is 47% Conservative/Cameron, 43% Labour/Brown. This tells a different story from that derived by totting up the votes and saying that progressive Lab-LD voters outnumber Conservative voters by 54% to 37%. However much we might wish otherwise, a Cameron-led government has greater public appeal than a Brown-led government. The margin is not great; and it is far less than it was for most of last year. But the notion that a Lab-Lib coalition would automatically command majority support is simply wrong.
You can read his full piece here.