From the latest Ashcroft mega-poll
We don’t often view polling data in this way partly because the sample sizes in the regular surveys are not really large enough to draw conclusions from sub-samples.
Lord Ashcroft gets round this by using very large samples with the result that for poll watchers like me his detailed data can provide good insights and pointers.
Clearly the top two, UKIP and LAB, have seen the most new support coming to them and are probably the most interesting. The UKIP chart does make the point that ex-CON voters are important but still only account for 45% of current support.
The LAB chart shows just how important 2010 LD switchers are to Ed Miliband.