Pollster ICM said its snap verdict of a narrow victory for David Cameron in the first of the leaders’ election broadcasts represented the company’s “best guess” of the nationwide response.
For its Guardian poll, ICM gathered 3,650 adults in an online survey earlier this week with each of them agreeing to watch the full 90 minutes of the Sky/Channel 4 Battle for Number 10 broadcast.
In the first few minutes after the programme, 1,123 of them returned to the pollster for a second survey on what they had seen, producing “ICM’s best guess on what a representative sample of the voting population would say had they all watched the programme”.
The group was weighted to all British adults, reflecting recall of their 2010 voting intentions.
Amid other findings, 46% felt that Mr Cameron had the best arguments, as against 44% who said the same of Mr Miliband.
The Prime Minister was judged marginally more convincing than the panel, by a difference of 48% to 43%. The ICM panel also felt Mr Cameron better answered the questions he was asked, winning on this measure by 44% to 37%.
Asked whether the programme might make their vote change, 56% of floating voters said they were more likely to vote Labour, compared with 30% more likely to vote Conservative. Those in this section of the group were only a very small sub-set of the wider group.