This polling has been carried out before and after every debate. But I understand that the Tories have not seen it. Interestingly, it shows the Lib Dems doing well before the first debate—at that point they had a net momentum score of 23, eg the percentage of people thinking they were gaining ground minus those who thought they were losing ground was 23. This was at a time when the Tories were on four and Labour minus seven. After the debate, the Lib Dems rocketed up to 77 and the Tories and Labour fell back to minus 21 and minus 24, respectively.
The Tory number remained negative from then until after the third TV debate when it jumped from minus nine to plus 24 (the fieldwork for this wave finished on Saturday). Meanwhile, Labour went from minus 39 to minus 61 after the final debate. The Lib Dems are still in very positive territory, but they have fallen back from 58 to 50.
This data would suggest, rather against some of the current polling, that the Tories are likely to pick up support in the final few days.
One other interesting stat worth noting is that 46 percent of those surveyed expect Cameron to be PM after the election and only 16 percent expect Brown to be so. Clegg is at six and don’t know at 32.