With the opinion polls consistently showing that Scotland is set to vote to Remain in the European Union on June 23rd (the latest estimate from TNS released last week suggested that, after excluding Don’t Knows, as many as 71% might do so), there seems to be more interest north of the border in discussing what might happen if the UK as a whole were to vote to Leave than considering the merits or otherwise of remaining in the EU. Last week the former Prime Minister, John Major, and the Chancellor, George Osborne, both warned that a vote to Leave could well trigger a second independence referendum – and argued that was one reason why voters across the UK should vote to Remain.
But is this expectation a reasonable one? If it is, then one thing we should be able to demonstrate is that there is considerable evidence that a majority would vote in favour of independence should Scotland find itself heading for the EU exit door against its will. After all, Nicola Sturgeon has made it pretty clear that she is not minded to hold a second independence referendum unless there is clear and consistent evidence that a substantial majority would vote Yes.
For that position to arise there needs to be a substantial swing in favour of independence as compared with the current balance of opinion. The 13 polls conducted this year that have asked respondents whether they would currently vote Yes or No to independence have on average put Yes on 47% and No on 53%. In other words, Scotland currently remains divided down the middle on its constitutional future, with a small majority in favour of staying in the UK.
However, is there any reason to believe that such a swing would actually occur? For while the prospect of Scotland being ‘forced’ to leave the EU against its wishes would undoubtedly be regarded as an affront by many a supporter of independence, we should remember that it is how unionists would react to such an outcome that would determine whether or not there was a swing in favour of independence.
There is certainly one group of unionists who would not regard a UK-wide vote to Leave the EU with disfavour – those who themselves want to Leave. And we should remember that Leave supporters are a little more numerous amongst unionists than amongst nationalists. Polling conducted shortly before last month’s Holyrood election by Panelbase, Survation and YouGov found on average that 37% of those who voted No in September 2014 propose to vote Leave, compared with 30% of those who voted Yes.
In any event, eight polls have now asked people in Scotland how they would vote in a second independence referendum if the UK were to vote to Leave the EU. Of these, five also asked their respondents how they would vote now in an independence referendum, and thus provide us with a direct measure of how much opinion might shift in those circumstances. The following table summarises what these five polls found:
As we can see, every one of these polls found that rather more say they will vote Yes if the UK votes to Leave the EU than say they would do so if there were an independence referendum now. But the ‘swing’ to independence in these circumstances is not a large one – between 3 and 6 points – and averages around four and a half. Applying that swing to the average level of support for independence in all polls conducted this year suggests that a UK-wide vote to Leave the EU might just result in majority support for independence – but only just. At 51% or 52%, it would certainly fall well short of the 60% figure that we have been advised would be regarded by the SNP as evidence that it might be willing to take the risk of calling a second referendum.
We should note too that two of the three polls that asked people how they would vote in a second independence referendum should the UK vote to Leave the EU (including last week’s TNS poll) without also asking them how they would vote now, found that there would still be majority support for remaining in the Union. The average level of support for Yes in these three polls together with the five listed in our table stands at just 50%, with No also on 50%.
Of course, we should bear in mind that we are looking at what respondents say they think they would do under hypothetical circumstances. None of us can be sure how we will react in a situation we have not as yet experienced. Indeed, the reaction in Scotland to a UK-wide vote to Leave might in the end depend on what the fall-out from such a decision proves to be. But at the moment at least it is far from clear that a vote for Brexit would change the balance of public opinion on independence enough for Nicola Sturgeon to want to take the risk of holding indyref2.
About the author
John Curtice is Professor of Politics at Strathclyde University, Senior Research Fellow at ScotCen and at 'UK in a Changing Europe', and Chief Commentator on the What Scotland Thinks website.