A referendum is not like an election. While the two sides of the campaign produced lots of literature supporting their view, there wasn’t anything like a manifesto as such. How could there be, given those leading the campaigns were not those who would end up actually implementing the decision? As far as the referendum was concerned, Brexit did indeed just mean Brexit – no more and no less. Nothing on the ballot paper said it was specifically this sort of Brexit or that sort of Brexit.

This has left a certain void, and one that politicians and others have sought to fill. Naturally, they have largely attempted to do so with their pre-existing prejudices rather than evidence. To listen to some it would appear that Brexit was driven by people who wanted {insert policy idea that I wanted to begin with}. A lot of this has been around how important an issue immigration was to Leave voters, and too what extent this was an anti-immigration vote. The alternative argument is often that the vote was mostly driven by concerns about sovereignty and freedom.

At the simplest level, if you want to know why people voted for something… ask them.

In YouGov’s final poll they asked people to pick which one factor was most important to people in deciding how to vote. Among Leave voters the most popular answer was allowing Britain to act independently (45%), followed by immigration (35%) and the economy (8%). Full tabs are here.

Lord Ashcroft’s poll after the referendum asked leave voters to rank four possible reasons for the vote – sovereignty, immigration, the economy or the risk of future EU integration. 49% of Leave voters picked sovereignty as their first reason (78% as either their first or second answer), 33% of Leave voters picked immigration as their first reason (64% as either their first or second reason). These two issues dominate, but the structure of the question suggests that people couldn’t say “I didn’t care about this issue at all”, so its somewhat limited (tabs are here, the relevant questions are on page 256!)

In both of these examples sovereignty came top, followed by immigration. However, it’s possible that this was down to the particular options the pollster offered or the particular wording used in the question. One way of getting round this issue is to ask it as an open-ended question and allow people to say in their own words why they voted as they did – two other polls did this.

In Ipsos-MORI’s final poll they asked what issues would be important to people in deciding how to vote in the referendum, letting people pick more than one option. The interviewer then picked which category or categories matched their answer most closely. In this case immigration came top among Leave voters, picked by 54% (18% also said the cost of immigration on welfare and 12% said the number of refugees coming to Britain – though given people could choose more than one option these cannot be added together). The next highest option among Leave voters was 32% who said the ability of Britain to pass our own laws, followed by 19% who said the economy and 9% who said jobs.

The pre-election wave of the British Election Study did a similar thing, asking respondents to type in what the most important factor driving their vote was and coding it up later. Taking a word cloud of the responses gives one extremely prominent answer…


…but this is actually a little misleading. Once the answers are coded up individually sovereignty comes very narrowly ahead of immigration. Just over 30% of verbatim responses from Leave voters mentioned sovereignty or control in some way, just under 30% mentioned immigration in some way (the word cloud appears as it does because most people who mentioned immigration used the specific word immigration, but people who mentioned sovereignty used a variety of different terms like sovereignty, control, making laws and so on). Suffice to say, immigration and sovereignty were, between them, the main two issues driving the Leave vote.

Referendums and elections are complicated things, and the human beings who vote in them are even more so. Anyone who tries to boil down the referendum to one factor and say “this explains it all” will almost always be wrong. While the order of the two issues differs between polls, all the polling evidence is clear that Leave voters were most concerned about the issues of sovereignty and immigration, and anyone claiming they were motivated by one but not the other is very likely projecting their own views onto the voters.

While they were clearly the dominant issues, there are undoubtedly others too – for example, as John Curtice explores here, there’s a very strong correlation with views on the impact of Brexit on the economy too, so while immigration and sovereignty were strong factors in favour of Leaving, another important factor seems to be that most leave voters did NOT think that Brexit would bring economic damage. I should also give my usual reminder that people are not necessarily very good judges of what makes them vote. We are not particularly rational creatures and the way people vote at referendums and elections is not a dry comparison of policy offers or facts, but often a mixture of vague feelings, bias and heuristics – so things like a lack of trust in the traditional media and “experts” and a perception that the remain campaign were speaking for an out-of-touch establishment rather than ordinary people were probably also factors in driving the Leave vote.

In short – the factors motivating Leave voters are many and varied and 52% of the voters will, by definition, contain people with many, many different views and priorities. However, every effort to ask Leave voters why they voted to leave found sovereignty AND immigration as the clear big issues.

A brief election post-mortem before I get some rest – hopefully we will have an actual London result by the time I finish writing! It is almost exactly a year since the polling error at the last general election. Yesterday’s elections were the first real test of the polls since then (there was accurate polling for the Labour leadership election, but polling party members really is a completely different exercise).


Taking Scotland first, all the polls obviously had the SNP winning, but that was hardly a challenge. Perhaps the bigger challenge was second place. In the event Labour narrowly held onto second place in the constituency vote but were pushed into third in the regional vote – the polls conducted in the last few days of the campaign did get this right, but all the Scottish polls did underestimate the level of Conservative support, and apart from YouGov’s final poll there was an overestimate of SNP support in the regional vote (though many of the polls finished some time before the election – the TNS face-to-face poll in particular – so it may be that SNP regional support dropped in the final week.)

Constituency . Regional
FINAL RESULT (5th May) 22 23 8 47 23 19 5 42 7
YouGov (2nd-4th May) 19 22 7 48 20 19 6 41 9
Survation (1st-2nd May) 19 21 7 49 20 19 6 44 7
Panelbase (23rd-28th Apr) 17 23 6 49 19 22 4 44 6
Ipsos MORI (18th-25th Apr) 18 19 6 51 19 17 7 45 10
TNS (1st-24th Apr) 17 22 7 52 18 22 5 45 8


YouGov was the only company to poll in Wales, and thei final poll held up very well, with Labour, Conservative, Lib Dem and Plaid all well within the margin of error. The only fault was an overstatement of UKIP support.


As I write, the mayoral results STILL haven’t been announced, and given how late they were in 2012 I’m not waiting up to write about them. Based on the live count of the first 90% of ballots the polls seem to be roughly in line with the expected result, and projections of the second round score suggest the polls are going to be close to it. You’ll apparently find out around midnight so you can compare to the polls below… but I intend to be asleep.

First round . Second Round
Pollster Goldsmith Khan Pidgeon Whittle Berry Others Goldsmith Khan
YouGov (2nd-4th May) 32 43 6 7 7 5 43 57
ComRes (28th Apr-3rd May) 36 45 6 4 6 3 44 56
TNS (26th Apr-3rd May) 33 45 7 5 4 5 43 57
Opinium (26th Apr-1st May) 35 48 4 5 5 3 43 57
Survation (21st-25th Apr) 34 49 3 5 3 6 40 60

All in all, the performance of the polls was far more credible than last year, though it looks like there may still have been some issues with the Tories in Scotland (and to be fair, most of the polling companies have been very explicit in saying they are still addressing their issues and developing their methods – the problems of last year are not going to be addressed overnight).

On a personal note – I’m most relieved the broad narrative was right. After the general election there were plenty of people saying how they knew the Tories would win, their instincts told them they would, how could those silly pollsters not spot it? Well, many of us silly pollsters thought the Tories would end ahead of Labour too: questions on leadership and the economy favoured them, we expected the polls to move towards the Tories… but the data just kept on showing the parties neck-and-neck, and ultimately a pollster’s job is to measure the answers the public give us, not report what we think they should say. We trusted the data, but it turned out to be wrong.

This time round it was the other way round. I never quite believed that the Conservatives could come second in Scotland. Yes, Scottish Labour was a mess, but Scotland would surely never vote for the hated Tories. My instincts said it wouldn’t happen in the end. A few months ago when YouGov were the only company showing Labour and the Tories neck and neck in Scotland I worried whether we’d get egg on our faces, but the data said it was happening, and I had to have confidence in the methodology corrections we’d made and in what the data was telling me… and this time, the data was telling the right story and the Tories really did come in second. Phew!


Oldham by-election

One day I’m going to write a generic post by-election post labelled (insert constituency name here) that I can repost after every by-election. Until that day, here’s my traditional answer to what last night’s by-election tells us about the national political picture: not much.

By-election are extremely strange beasts. They take place in a single constituency that may be completely untypical of the country as a whole, they normally have no impact at all upon who will be running the country the next day, they have far greater campaigning intensity than any other election. After every by-election I post the same conclusion – if they show much the same as the national polls suggest they tell us nothing new, if they show something different it’s probably to do with the unique and different circumstances of by-election. In this case the opposition party has held onto a safe seat. This is exactly what we should expect unless they are tanking in the national polls, and Labour aren’t: despite Corbyn’s poor ratings and the constant news stories of Labour infighting their level of support is still pootling along at around their general election share. There is no reason to expect UKIP surges either – in the last Parliament UKIP had soared from 3% to the mid-teens, so almost every by-election saw them surging, but now we are comparing their support to what they got in the 2015 general election, after their breakthrough. This is a good local result for Labour, but doesn’t tell us much new.

That’s not to say it’s not important. By-elections have a significant effect on the political narrative and in that sense this is a very good result for Labour (or, depending on your point of view, for Jeremy Corbyn). If this by-election had gone differently it would have been part of a different narrative, it would have been all about Labour in crisis, their traditional working class support fracturing to UKIP. It would still have been over interpreting a by-election, but it would almost certainly have happened and it’s been avoided. In that sense, it’s an important victory.

A final note about the polling – there wasn’t any (I don’t know whether to be amused or depressed by the handful of comments I’ve seen about it being a another polling failure. Nothing to do with us mate!). By election polling used to be very rare, then in the last Parliament we were suddenly spoilt, with Survation and Ashcroft polls for most By-elections. This time we are back to having no real evidence to go on, to relying on what commentators have been told by the campaigns, what it “feels like” on the doorstep and in vox pops and all that sort of nonsense. I suspect the collective commentariat have got carried away with what would have made an interesting narrative to report, rather than dull old “safe seat held”. It’s a reminder that without any proper polling By-elections can be pretty hard things to call.

Just a quick line to point out that the Constituency guide part of the site has now been updated to reflect the general election results and the new MPs elected, including the target and defence lists for the parties (SNP and UKIP to follow). Before anyone points it out there’s still lots to do – including new swingometers and updating MPs profiles to reflect the reshuffles.

Last week Opinium’s Observer poll was conducted prior to the Paxman interview, so I wasn’t sure whether the poll from them tonight would be “post-debate” or not. In the event it is – conducted on Friday and late on Thursday night.

As with Survation’s poll yesterday there is no sign of any significant post-debate shift in voting intention, with topline figures of CON 33%(-1), LAB 33%(nc), LDEM 7%(-1), UKIP 14%(+1), GRN 7%(nc). Full tabs are here.

Asked who won they think won the debate 20% of people who claimed they saw at least some of it said Nicola Sturgeon won, followed by Cameron on 17% and Miliband on 15%. Leader ratings show some movement, but not quite as dramatic as those in Survation’s poll (that may be a result of question wording – Opinium ask a general question about how the leaders are doing, Survation ask specifically about how they’ve been doing in the last month). David Cameron’s rating here is unchanged on plus 1, Miliband is up six points on minus 15, Nick Clegg is up ten points on minus 30, Nigel Farage is up eleven on minus 13.