ICM have released the figures for a poll they carried out for Greenpeace in 6 West London marginal seats (Battersea, Ealing Central & Acton, Ealing North, Brentford and Isleworth, Hammersmith and Feltham & Heston) about Heathrow expansion which also includes voting intention figures in those seats.

The topline figures in the poll, with changes from the notional figures at the last election (I’m using Rallings & Thrasher, since I’m assuming that’s what ICM used when coming up with weightings), were CON 40%(+8), LAB 41%(-1), LDEM 13%(-8). This represents a swing of 4.5 points from Labour to the Conservatives. At the time the poll was taken, on the 16th and 17th December, ICM’s national poll was showing a swing of 4 points to the Conservatives, so there is no significant difference between the swing here and nationwide, though the changes in the individual party shares of the vote are better for the Conservatives and Labour and worse for the Lib Dems than in national polls.

Asked about their attitude to a 3rd runway at Heathrow 34% of respondents said they were supportive, with 45% opposed. Those opposed also tended to be firmer in their opposition – the supporters were roughly half and half between strong supporters and “tend to support”; three-quarters of those opposed were strongly opposed.

Asked how it would affect their vote at the next general election if Labour went ahead with a third runway, 10% said it would make them more likely to vote Labour, 23% said it would make them less likely to vote Labour. As regular readers will know, not least because I bang on about it whenever anyone asks such a question, I am highly sceptical about questions asked this way. Of the people who say a decision to build a third runway would make them more likely to vote Labour, the overwhelming majority are people who say they would vote Labour already. Of the people who say it would make them less likely to vote Labour, the large majority say they would vote Conservative or Lib Dem tomorrow anyway. Too many people in questions like this are committed voters who are just using it to send a message, not people whose vote is actually up for grabs.

11 Responses to “Poll of West London marginals”

  1. The weightings used ( given on page 11 of the detailed data ) seem to indicate the vote at the last GE was something around Con 32 Lab 45 LD 18 Oth 5
    The data on how people say they voted in 2005 and currently shows more LibDems changing to Labour net 9 than Conservative net 4 which is contrary to recent national polls .

  2. The Rallings and Thrasher notional vote at the last election in those seats was CON 32%, LAB 42%, LDEM 21% Others 5%. The targets for weighting are adjusted to take into account ICM’s estimates of false recall.

  3. Thanks for that explanation Anthony .

  4. It think it’s right to be sceptical about those questions asking whether people’s opinions on the 3rd runway might affect the way they might vote, not least because it’s a truism that people will use any available cipher to promulgate their political viewpoint.

  5. Anthony,

    The large Libdem fall fits in with what I think may well happen in Scotland.

    As I’ve noted before with 40% of the Scottish Libdem vote in the approximately 205 of the seats they hold I think that the squeeze will fall predominantly in seats they don’t hold and therefore although they could have a big drop in their national vote they won’t lose as many seats as the predictors suggest.

    Is there any evidence to suggest from marginal polls that the Libdem vote is holding up particularly better in seats the LibDems hold?.

    I know you have build an element for incumbancy in to your calculations but is it the same for all the parties, and does it alter depending on whether the party is in accendency or not?

    I can understand the reluctance to get involved in that kind of thing as it can easily go from being informed judgement to supposition and speculation.

    Having said that from the perspective of Scotland I’d be looking at the Libdems falling to on or below 10 seats with it accounting for over 50% of their vote.

    Out of interest has anyone got figures for the national breakdowns in terms of percentage of total vote in seats held for the main parties.

    I’d be interested to see it because it might give an insight in to how vulnerable the Libdems are to reaching a tipping point between a good result on a lower percentage and a crash in the number of seats held.


  6. The Labour position seemed to be driven by the 18-24 cohort who went L67% to C23%. ICM seemed have found it hard get a reasonable sample of the age group and they had to be weighted up by more than half.

    A survey of voter registration levels across the whole London by NOP last year had more than a quarter in this group not on the register.

  7. I thought as much when I read the contrived piece in the Sunday Times. Other polling has suggested that the wider public back the third runway, and recognised that many people living near Heathrow work there. ICM were very tardy putting up these figures on their website. Shouldn’t there be a requirement that they do so once partial reports of their findings are being made in the newspapers?

  8. Conor – the disclosure rules of BPC are that those pollsters who are signed up (which includes ICM and the other main companies) will put the tables up on their website (or provide them if asked) within 2 days.

  9. Peter , the data from the big marginals poll some months ago now certainly showed LibDem support holding up better in LibDem seats .
    I agree with Mike , the results for the subsample for 18-24 yr olds in this poll looks odd , but with these small subsamples there is usually a freak or two .

  10. On Mike’s comment about the big upweighting needed for the under 24s, my impression (I haven’t taken the time to collate the figures and look at them over a large number of polls) is that this this is a pretty common occurance – under 24s seem to be an age group that are often under-represented in the raw samples who need weighting upwards (understandably enough I suppose, since they are most likely to be mobile only or to be out having an active social life!)