Is the fall in Reform's poll ratings a mirage?
Welcome to the 196th edition of The Week in Polls (TWIP), which dives into the data to see if it is true that the apparent fall in Reform’s support in the polls is simply a mirage caused by changing levels of people saying ‘don’t know’.
That is followed by a summary of the latest national voting intentions 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, including:
Why I’m relaxed about polling showing people not knowing what has happened to net migration in the last year;
The first data related to Robert Jenrick’s defection; and
How MPs underestimate support for environmental policies.
If you are not yet a paid subscriber, you can read all ten by starting a free trial now:
For more polling news as it comes in during the week, you can also follow The Week in Polls on Bluesky.
Before that, a correction to last time’s edition. In an impressively stylish/incompetent (delete as appropriate) error, I managed to misquote myself in the caption to a graph. I should have written that “The 2025 figure here is for all of 2025, and hence higher than my 2%, which is for 2025 after the May elections.” Instead, I wrongly said that my 2% figure was for just the last quarter of the year. Thank you to John Swarbrick for pointing out the mistake; a free annual subscription to the paid-for version of this newsletter has gone to him.
And with that, on with the show.
Reform’s fall in the polls: mirage or reality?
If you stare too closely at individual voting intention polls, it has been a rollercoaster few weeks. From a peak earlier in 2025, Reform’s support slipped back a few points before the festive season. That seemed to have levelled off in December, until around Christmas time we had a pair of polls each putting Reform down a further three points. But then came a run of polls just before and after the New Year showing Reform edging up again, before most recently we’ve had a trio of polls showing Reform slipping once more.
(In all this, I am counting polls by when their fieldwork was done, not by when they were published. Hence, for example, Deltapoll’s most recent figures count as a pre-Christmas poll rather than a post-New Year one.)
One of those most recent trio, the YouGov one putting Reform on 24%, had the eye-catching characteristic of being the lowest Reform share in any poll since April.
But take a step back, and it is all a bit calmer when you look at the bigger picture. Across the second half of December and January so far, it all pretty much cancels out with Reform on average at most only falling back a further sliver, though certainly still down on its peak last year.
Yet perhaps even this bigger, calmer picture is a mirage. Stephen Bush wrote for the Financial Times that:
What is giving the impression of a plateau, or even a dip in Reform’s vote share, is that people who voted Labour in 2024 first shifted from Labour to “don’t know” (which doesn’t get tallied in the polls recording “headline” voting intention in the UK, though it does in other countries) and are now switching from “don’t know” to the Greens or Lib Dems. That decreases the share of people voting Reform even though the actual number hasn’t fallen.
Let’s have a look at the data and see how that mirage argument holds up.
For each pollster with polls out whose fieldwork was conducted this year, I have taken the average of the data from their polls this year and compared that with their poll with the highest Reform showing last year. (Where the same pollster had more than one poll with that peak score, I have taken the most recent.)
The figures I have compared are for Reform’s support before the removal of the ‘don’t knows’. As each pollster’s methodology, and published crosstabs, varies, there is also some variation in what else is excluded other than the removal of the ‘don’t knows’. But using the data prior to the exclusion gives us a consistent picture of whether or not it is a change in the level of ‘don’t knows’ that is apparently inflating Reform’s support.
This is the picture that emerges:1
A fairly straightforward conclusion this week, then. According to More in Common’s figures, Stephen Bush is right about the decline in Reform’s vote being a mirage of the ‘don’t knows’. But every other pollster we have data for so far this year says otherwise.
Overall, the data tell us that the fall in Reform’s support has been genuine.
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 (or an extra 12 months on your existing one). Factual errors qualify rather than grammatical errors or disagreements over interpretation, with my decision being final. Messages about both of those are always very welcome, though.
Voting intentions and leadership ratings
Here are the latest national voting intention figures. As with Reform’s support, that of the Conservatives certainly moved last year, in their case rising slowly through the last few months of the year. So far this year, that rise has (probably) continued a little but we don’t really have enough data to be sure.
The table is also online here. It is updated regularly through the week with new polls.
Next, the latest seat projections from MRPs and similar models, also sorted by fieldwork dates. As these are infrequent, note how old some of 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.
Elsewhere from me
Catch up on the previous two editions
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Public’s views on immigration are more accurate than the polls might make you think, and 9 other polling insights you shouldn’t miss
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.
More in Common finds that people still think net migration is rising, despite the fact it fell sharply last year. Should we despair? No, but before I get to that here is their latest data:
