ComRes released their latest poll of marginal seats today. As regular readers will recall, ComRes’s marginal polls cover the 40 most marginal Con-v-Lab seats (25 Conservative held, 15 Labour held). Unlike Lord Ashcroft’s marginal polls (which are actually a series of individual constituency polls in seats that are marginals, which we can aggregate together to get an extremely large sample across a group of marginal seats) ComRes’s poll is a more traditional marginals poll – a single poll of a group of marginal seats, meaning it gives us a measure of those seats as a whole, but has far too few people to tell us anything about the individual seats within that group.

Latest voting intention figures in these marginals with changes from the last time ComRes polled them in September is CON 31%(+1), LAB 39%(-2), LDEM 7%(+1), UKIP 18%(+1). These seats had Labour and Conservative equal at the last election so an eight point lead here is the equivalent of a four point national swing and a one point Labour lead in national polls…pretty much exactly what the national polls have been showing lately (actually if you look at the crossbreaks of the poll they suggest a swing towards the Conservatives in the Conservative held seats, a swing towards Labour in the Labour held seats, but given the sample size of those two groups and that the poll is only weighted at the level of all forty seats I wouldn’t put too much weight on that).

Note also that, judging from the tables, ComRes have switched over to prompting for UKIP in their main voting intention question in this poll – as with their last national poll, it does not seem to have had a major effect (UPDATE – I think this is because ComRes have changed turnout weightings, so that there is a tighter turnout filter for the Greens and UKIP than for the main parties). Tabs are here.

There should be another batch of Lord Ashcroft polls of individual marginal seats later this week.


ComRes’s monthly online poll for the Indy on Sunday and Sunday Mirror is out tonight and has topline figures of CON 30%, LAB 34%, LDEM 8%, UKIP 19%, GRN 3%. Tabs are here.

On the face of it there is very little change from a month ago, the Conservatives are down one, Lib Dems up one. However, there is actually an important methodological change. As regular readers will remember, last month ComRes did a split sample experiment in their online poll, with half the sample being asked voting intention with UKIP in the main prompt, half not. This apparently made 5 points difference to UKIP, with the prompted half of the sample showing UKIP up on 24%. ComRes have now switched over to prompting for UKIP all the time in their online and telephone polls, but it obviously didn’t have the same dramatic effect in this month’s poll. I suppose comparing prompted-poll to prompted-poll UKIP are down 5 points since last month, but perhaps last month’s was an anomoly and the impact of prompting is just less than the split-sample experiment suggested.

ComRes’s press release suggests they have also tweaked their weightings this month. I’ll update with details once they are confirmed, but looking through the tables nothing jumps out at me so it is probably relatively minor.


We’ve had a busy day of voting intention polls today, four polls from Populus, Ashcroft, YouGov and ComRes, and three of them showing the same lead. Topline figures are:

Ashcroft: CON 31%, LAB 31%, LDEM 7%, UKIP 18%, GRN 5% (tabs)
Populus: CON 34%, LAB 36%, LDEM 8%, UKIP 13%, GRN 3% (tabs)
YouGov/Sun: CON 32%, LAB 32%, LDEM 8%, UKIP 18%
ComRes/Indy: CON 30%(+1), LAB 30%(-5), LDEM 9%(-1), UKIP 19%(+4), GRN 4%(nc) (tabs)

Leaving aside the tendency of Populus to show higher support for the Conservatives and Labour and lower support for others, the picture is pretty consistent. Three polls (as well as YouGov and Opinion polls at the weekend) are showing the same story – Labour and Conservative equal, and UKIP still polling very strongly. Whether there is any link there is a different matter – perhaps UKIP’s ongoing rise has attracted people who were previously saying they’d vote Labour (though not necessarily people who voted Labour in 2010) who see UKIP as a better anti-government vote, but there is always churn beneath the topline figures and things may very well be more complicated than a straight transfer between the two.


ComRes have done their monthly online poll for the Independent on Sunday. Topline figures are CON 31%(+2), LAB 34%(-1), LDEM 7%(nc), UKIP 19%(nc), GRN 4%(nc). For clarification, given some of the misunderstandings on Twitter earlier today, this is using ComRes’s normal methodology and prompting, they haven’t changed anything (I have no idea if they intend to do so or not… though I expect they’ll be getting a lot of people asking them tonight!). The sample size however was smaller than usual, as with the other half of the sample ComRes carried out an experiment asking the voting intention question including UKIP in the main voting intention prompt. The result using that different method was CON 29%, LAB 31%, LDEM 7%, UKIP 24%, GRN 5%.

Now, I should underline the importance of noting that this is just one poll. It is comparing two samples of 1000 or so people, with the usual margins of error that implies – so not all the difference will necessarily be prompting, some could just be normal sample variation. Please don’t go away with the idea that prompting for UKIP will always has the effect of bumping up UKIP by 5% – it’s just one data point. I think it probably does make a difference (we’ve tested in the past), but five points does seem rather high. Also remember that prompting may affect different methods differently, so the way it affects a ComRes online poll using their methods would not necessarily reflect the way it would affect any other poll (I am personally intrigued by the possibility that prompting may have a different impact in telephone polls, where people may feel obliged to pick one of the options offered by a human interviewer, than in an online poll where it’s just clicking through to another list of options – but obviously I don’t have phone polls to test it on!)

Knowing that prompting does make a difference – something that pollsters knew anyway – doesn’t actually get us any closer to an answer to the real question though, whether prompting for UKIP produces more or less accurate results in GB election polls. It the ComRes figure of 19% more or less accurate than the figure of 24%? Whether polls prompt or not for UKIP is often a issue that produces a lot of comment. Part of that is from people whose concern is, shall I say, more to do with maximising the reported level of support for UKIP than it is to maximise the accuracy of polling. Part of it is that, prima facie, it does seem somewhat strange that a party (normally) running in third place isn’t prompted for when the party that’s (normally) running in fourth place is. Another part is people looking for an explanation for the big difference in reported levels of UKIP support between different pollsters; typically the companies showing the highest levels of support, Survation and Opinium, show UKIP at about twice the support of ICM or MORI, who typically show the lowest. In the latter case I think the attention is misplaced – the reason for the biggest differences in levels of UKIP support in the polls appears to lie elsewhere – companies like Opinium manage to show some of the higher figures without any prompting! Rather they appear to be a contrast between telephone polling and online polling, for some reason online polls show consistently higher levels of UKIP support than telephone polls. That may be something to do with the mode (perhaps people are more ready to admit they are voting UKIP to an anonymous computer screen than to a human interviewer) or it could be something to do with sampling (for some reason phone samples have fewer of the sort of people who vote UKIP than online samples do).

As a pollster it is more important that methods produce the most accurate results than it is whether they appear “fair” (and certainly it’s more important to be accurate than to produce the higher possible score for UKIP!). The fact is that there isn’t a hard and fast rule about when you do and don’t prompt, we don’t have the evidence to say the cut off point is x% support, or y place, or z number of MPs. It’s a matter of judgement. We know from experience over the last couple of decades that prompting for smaller parties tends to overestimate their support (probably because it gives them a prominence and perception of equality with the major parties that may not be there among the general public), we also know that in the 1980s NOT prompting for the Lib Dems used to underestimate their support, so getting it wrong either way can produce error. Sometimes you can get it wrong by prompting, sometimes you can get it wrong by not prompting. There is no real way of knowing when a party switches from a position where prompting risks overestimating them to one where not prompting risks underestimating them – but clearly we are equally keen to avoid both errors. If UKIP establish themselves to the point that they have lots of MPs, consistent support over time, have known people and policies, are treated as a major established party that is given equal treatment by the BBC and OfCom and so on the time will come when the risk of not prompting outweighs the risk of prompting (it has already come, for example, in European elections)… but when you reach that point? It’s a judgement call.

It’s in a bigger context too. The last general election was held in the middle of “Cleggmania” and a surge of enthusiasm for the Liberal Democrats. The polls overestimated their support. The European elections earlier this year saw a great big surge of enthusiasm for UKIP… and of polls in the last week all but one company overestimated their support. In the Scottish referendum I don’t think anyone could deny that the YES campaign were the more enthused, and the polls seem to have all slightly overestimated their support. I may very well be reading something into these that isn’t there, but you get my drift – polls may be overestimating support for parties and movements that have particularly enthusiastic and zealous supporters. There’s also that unexplained difference in UKIP support between telephone companies and online companies, and what might be behind that. Getting UKIP right at the next election is the big challenge facing pollsters, but its about more than just prompting.


Sunday Polls

I’m about to head up to Birmingham, so won’t necessarily be around much for the next few days (not least, when Lord Ashcroft releases his latest marginal poll at 2pm today I’ll be on a train!), but here’s a quick summary of today’s other polls.

ComRes in the Independent on Sunday have topline figures of CON 29%(-3), LAB 35%(+1), LDEM 7%(-1), UKIP 19%(+1). Changes are from their previous online poll a month ago. Tabs are here.

Opinium for the Observer have toplines of CON 32%(+3), LAB 34%(-3), LDEM 7%(nc), UKIP 17%(-2). Changes are from a fortnight ago.

Finally the weekly YouGov poll for the Sunday Times has toplines of CON 31%, LAB 36%, LDEM 6%, UKIP 15%, GRN 6%. While some other pollsters have already shown the Greens in fourth place, this is the first time that YouGov have shown them catching the Liberal Democrats. Tabs are here.

There is no obvious impact in the polls from the Labour party conference – ComRes have their lead up, Opinium down, YouGov not far from their recent average. In YouGov’s survey they asked if Labour’s conference made people more or less positive about Ed Miliband – 13% said more positive, 15% more negative, 54% unchanged.

YouGov also had several questions on Iraq, showing majority support for British airstrikes against ISIS (58% support for attacks in Iraq, 53% for attacks in Syria) but continuing opposition to putting ground troops back into Iraq (26% approve, 53% disapprove). YouGov also asked about whether Britain should co-operate with Assad or Iran in fighting ISIS. People are evenly split over Assad – 36% think we should co-operate with the regime, 34% that we should not. With Iran people are far more supportive of co-operation – 54% of people think that we should co-operate with Iran, 18% are opposed.