The tables for Ipsos MORI’s poll are now up on their website, so we can dig about and see what’s actually happened.

Regular readers will know that the big difference between MORI and other pollsters is that MORI do not politically weight their sample. All the pollsters including MORI weight their samples by known demographic figures like age, gender, social class and region. All except MORI also use political weighting, normally weighting by how people claim they voted at the last election.

There’s a much longer explanation of why most pollsters do this and MORI do not here, but the very short version is that people aren’t very good at recalling their 2005 vote. ICM, Populus and ComRes take the view that past recall is pretty stable over time and can be estimated well enough to weight by, MORI take the view that it’s too unstable and should not be used for weighting. The result is that MORI’s samples run the risk of varying politically from month to month more than those of other companies (though MORI would claim the opposite – that other companies risk weighting out genuine public volatility). In a case like this, it raises the question of to what extent the shift is down to people changing their minds, and what extent it is just a more Labour sample.

In MORI’s poll last month which showed a 17 point Tory lead, amongst those who voted in 2005 32% said they voted Conservative, 43% Labour and 16% Liberal Democrat. In this month’s poll which shows a 6 point Tory lead the figures of recalled 2005 vote break down as Conservative 29%, Labour 46% and 16% Liberal Democrat – so a 6 point change in the recalled lead from 2005. (For reference, ICM weighted their sample so recalled 2005 vote was Conservative 33%, Labour 38% and Lib Dem 22% – even they don’t weight to the actual figures because of false recall).

So part of the reason for the shift in MORI’s voting intentions since last month is that their sample appears to have had significantly fewer people who voted Tory in 2005 and significantly more people who voted Labour in 2005 (again, from MORI’s point of view at least some of that would be changes in the level of false recall).

However, this does not explain the whole difference. If you look at the rest of the survey’s innards, there is real movement in Labour’s favour too. Likelihood of Labour supporters voting has increased, that of Conservatives deceased – but in both cases the change is too small to be significant. More interestingly there was an increase in the likelihood of people who voted Labour in 2005 to vote Labour now – in October 65% of former Labour voters said they would back the party this time, this month 72% of Labour’s 2005 voters said they would back the party.

In conclusion, while a lot of the massive shift in voting intentions in this poll appeares to be down to sample variation, there’s a modest firming of the Labour vote too. We should still wait for some more polls to see whether that itself is real, and whether other companies also pick up a firming of the Labour vote. I wouldn’t, however, expect any company using political weighting to show quite such a narrowing of the lead.


109 Responses to “More on Ipsos MORI’s 6 point lead”

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  1. “There are 3 reasons why you don’t need to worry

    1 It is a rogue poll
    2 It is a rogue poll
    3 It is a rogue poll

    Just thought of another

    4 It is a rogue poll

    Is that the hands over ears “nanananan it’s not happening” approach.

    This poll is quite climatic of the tory overall drops in most polls in the last few months.

    The big one may have stayed the same, but they’ve lost ground to Labour on many major sub topics.

    I think the tories will be very worried. As there poll lead certainly isn’t growing.

    An intelligent view will suggest that it will probably shrink a fair bit before now and then.

    Watch Cameron in the news, basically now backing Labour’s approach to deficiet.

    Citing “growth” and not cuts.

    That’s a man who’s realised that things could possibly be turning

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  2. As for the poll, I actually think people think into it too much.

    Any Labour gains in polls are either:

    1: Ignored by the media, until they change back
    2: The media say there’s something wrong with the poll

    Every tory drop since conference season, people have blamed the poll it’s in. Including this web site.

    It seems that tory gains are just “normal”, but Labour gains “it’s the poll!”.

    Personally, if you are canvassing, and looking at the political forums on newspapers, I think it’s personally obvious that the tories polling is going nowhere but down.

    Like it or not, they’ve been shown up on the credit crunch. Cameron is in the media today telling us all that backing “growth” is actually the way out. What Brown has been saying for nigh on 2 years.

    Europe was a clanger. If you read the forums you would have seen a huge majority of irate tories, thinking they’ve been sold out, and vowing to head to UKIP.

    Like it or not, the lack of real accountable policy is still hurting them. Cameron can laugh all he wants about Labour policy, when Brown can just chirp back “what are you actually going to do?”.

    Personally, I can quite easily see that when your campaign is built on sand foundations, it won’t take much to knock it down.

    No matter how much they hate a leader (see Maggie Thatcher) they will always stick with the status quo, if the opposition hasn’t convinced them that they are up to it themselves.

    Continued growth in the future, will do nothing but hurt Cameron. As he’s been the one in the last 2 years, telling us all about how cuts are the only option. And how Brown has been lying to us all about being able to ride growth.

    Well Dave, if the economy does have a big rise, cuts are the political equivilant of retiring your prize greyhound after his 10 wins in a row, as you don’t want to risk wasting £20 on food, in case he doesn’t win 11.

    So we have Dave in the media, backing growth, and going off the “age of austerity approach”.

    The polls will always fluctuate as no one has a clue what Cameron is, and what he plans to do.

    The more he flip flops, the more faith will drop.

    I think the tories will win, but this claims about going into a election with a 13 point poll lead are wrong.

    I’d be amazed if it wasn’t closer to 7 or 8 points. As your poll suggests.

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  3. @ CHRIS:-

    “Citing “growth” and not cuts.”

    You do live in a very one dimensional world Cris.
    The two are not incompatible.

    Indeed if you believe-as Cameron does-, that defict financing can be inimical to real sustainable economic growth, then you prefer-as he does-incentives to employment in the private sector to unproductive expenditure in the State sector.

    It’s a balance Chris-not one or the other.

    By the way-seen the latest poll?
    Confusing isn’t it when you’ve just got all excited.

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  4. Dear Chris- of course we need growth. We are stuffed without it.

    But we need real growth and we need to rebalance (a good labour spin word there for you) our spending.

    Brown has been saying we need growth you say? That growth is the answer?

    Well why, despite ‘growth’, then did Brown run deficits every year since 2001 after he stopped sticking to Tory spending plans? We have a massive structural deficit. Growth alone will not fill that gap, which is why Cameron also talks about spending.

    As by now you will know – we have a new poll putting labour on 22 and a tory lead of 17. You are the clever one; go figure.

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  5. Dear Chris

    In the by election the labour vote was 12,231, 59%)

    In 1997 when the seat was Glasgow Springburn, Martin polled 22,534, 71% .

    So your contention about Labour increasing its vote seems a little wide of the mark.

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  6. Chris,
    the fact that you suggest Cameron needs to win lots of Glasgow Easts to win the election shows little or no understanding. It would have been equivalent to suggesting in 1997 that Labour neeeded to win lots of Kensington and Chelsea’s for them to get in power.
    Cameron’s battleground is not the likes of Glasgow East, its the likes of Dartford,Chorley,Tynemouth and Bolton.
    Nobody ignores Labour’s increase in the polls, but when one shows them on 31 then the next on 22 they need to be treated with caution, not used as the fuel for a one sided, unfounded rant.

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  7. It must have been soul destroying to see the latest Angus Reid poll down at Labour HQ. Just when they thought they might be catching up as well!

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  8. Of course one of the other factors with polls (even, to a lesser extent exit-polls) is how many people lie if they’ve voted for a seemingly unpopular party. Often this can be the encumbent.

    The Scottish vote certainly will play a big part this time.

    The apathy wich has coloured recent votes may do also, especially if we are subjected to a near 6 month unofficial campaign following the pre-budget report.

    I still think the forthcoming GE might be very close indeed, and psephologically very interesting.

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  9. What I have found, when currently canvassing for Labour on the doorstep, is that there isn’t the hostility towards the party that I remember throughout the 80s.

    I think the firming of the Labour vote in this poll would seem to reflect that fact,

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