How do the polls stack up against actual election results?
Welcome to the 184th edition of The Week in Polls (TWIP), which takes a look at a pair of real election results to see how the opinion polls performed.
That is followed by a summary of the latest national voting intention polls, seat projections from MRPs and the most recent party leader ratings.
Subscribers who pay for the full edition can also read ten insights from the latest polling and analysis. These include:
Whether people view various politicians as human or robotic;
Polling on Palestine Action;
What do the Green, Reform and Lib Dems have in common?
If you are not yet a paying subscriber, you can read all of those ten insights by starting a free trial now:
For more polling news as it comes through the week, you can also follow The Week in Polls on Bluesky.
And with that, on with the show.
Labour Party Deputy Leadership election
The result was:
Lucy Powell: 54.3%
Bridget Phillipson: 45.7%
Winning margin: 8.6%
The previous polls for Powell versus Phillipson head-to-heads came from YouGov (one poll), Find Out Now (one poll) and Survation (three polls). Excluding don’t knows those figures were:
YouGov: 12% Powell lead
Find Out Now: 12% Powell lead
Survation: 22% Powell lead, 34% Powell lead and then most recently
18%15%1 Powell lead
A pretty good result therefore for YouGov and Find Out Now (though the latter’s ‘have you voted?’ question got 68% saying yes).2 But some questions for the Survation/LabourList polling methodology, which uses readers of LabourList who also say they are Labour Party members. (For a comparison with how ConservativeHome’s polls of Conservative leadership races do, see my previous analysis and for my own experience with Lib Dem Voice polls, see here.)
However, as far as I can tell, all the polls above were of Labour Party members, but the contest had a wider electorate. To quote the Labour Party, “Affiliated supporters who are not otherwise members of the Labour Party as defined above shall be eligible to vote provided that they meet the following criteria…”
Even so, I think it is fair to compare these polls with the result in that the polls were presented as being guides to what was happening in the election overall. (I also have not come across any examples of the camp that was behind knocking the polls for excluding these other voters.)
A side note about the turnout which was under 20%:
(The re-election referred to was an all-member ballot for Liberal Democrat President.)
To be fair, Jessica made a powerful point in reply:
Also worth noting:
And while I’m being fair to journalists, I should also quote the following written in advance of the result by George Eaton in the New Statesman:3
Where both sides agree is that the contest could be closer than some assume. Membership polling so far has favoured Powell, who won 269 Constituency Labour Party nominations to Phillipson’s 165, but two factors give the latter’s supporters hope .. trade union support … and … London.
This time, it was closer than the polls were telling us. When the reverse is true, I have a habit of politely poking fun at people who thought they knew better than the data. So this time around, kudos to George for being right.
Caerphilly Senedd by-election
As I reported last week, there was one poll for this contest, conducted by Survation, which put Reform on 42%, Plaid on 38% and Labour on 12%.
The result was Plaid 47% (+9 on the poll), Reform 36% (-6) and Labour 11% (-1).
The bad news then for that Survation poll was that it had a different party in the lead from the party which won, and its vote share errors were outside the usual 3 per cent margin we can discount.
But… it’s worth also pointing out that in an important way the poll got the election right. Although this was a Labour seat with an 18% majority in the previous contest, the poll was right in pointing out that Labour had collapsed and the race was now Plaid versus Reform.
If you view an important purpose of pre-polling day campaign polls as being to inform voters about how best to use their votes, then Survation got it right. It correctly told people the information needed to decide whether or not to vote tactically and if so for who.
That is a win for constituency polling - and by implication for MRPs too.
Survation’s poll certainly compares well with:
Peter Kellner has also looked at the by-election result, putting the voter shares in historic context.
UPDATE: See my corrections and clarifications for this piece here.
Elsewhere from me…
If you spot a factual error…
Borrowing an idea from Stuart Ritchie and others, if you spot a factual error in an edition of this newsletter, I will give you a 12-month free subscription to the paid-for version of this newsletter (or an extra 12 months on your existing one). Factual rather than grammatical errors, and factual errors rather than disagreements over interpretation. Though messages about both of those are always very welcome.
Voting intentions and leadership ratings
Here are the latest national voting intention figures from each of the pollsters currently active, with a bit of a sign in the last week of the Reform vote dropping and of the Green vote rising.
So far, the overall picture is sufficiently similar between pollsters that, Find Out Now aside, the variations in their figures do not particularly catch the eye. But with four parties starting to bunch together closely, small variations may start producing rather different headline pictures about which party is placed where.
The table is also online here and is updated regularly through the week with new polls.
Next, the latest seat projections from MRP models and similar, also sorted by fieldwork dates. As these are infrequent, note how old the ‘latest’ data is.
Finally, a summary of the latest leadership ratings, sorted by pollster name:
The table is also online here with additional details and is updated regularly through the week as new data comes out.
For the historic figures for both voting intention and leader approval, including Parliamentary by-election polls, see PollBase.
Catch up on the previous two editions
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Robotic or human? What people think of politicians, and other polling news
The following 10 findings from the most recent polls and analysis are only for subscribers who pay for the full edition, but you can sign up for a free trial to read them straight away.
Polling by More in Common for Grayling Media asked people: “When you hear the following politicians in the media, would you describe them as more robotic or more human?” and the results were illuminating…
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