Today marks the third anniversary of the EU referendum in which the country voted narrowly (by 52% to 48%) in favour of leaving the EU. Since then, the country has spent much of the last three years debating how the process of leaving has and should be handled, the terms on which we should aim to leave, and even the merits of the original decision itself. The debate has precipitated a general election and resulted in the downfall of a Prime Minister. The one thing that has not happened is Britain making its exit from the EU – thanks to the repeated refusal of the House of Commons to accept the terms of the withdrawal treaty that was negotiated with the EU by the UK government. Instead the country is awaiting the arrival of a new Prime Minister who will be charged with the task of solving in three months a Brexit riddle that Theresa May was unable to solve in three years.

One might imagine that the difficulties that have beset the withdrawal process would have had an impact on support for the principle of remaining or leaving the EU in the first place. But of that there is remarkably little evidence. Our poll of polls of how people would vote in another referendum continues to report that the country is more or less evenly divided between Remain and Leave, much as it was three years ago.

True, as has been the position ever since our poll of polls series began at the beginning of 2018, the balance of support is now tilted in favour of Remain rather than, as in the referendum, in favour of Leave. Indeed, the current average of Remain 52%, Leave 48% is the exact mirror image of what emerged from the ballot boxes in June 2016.

However, this does not mean that there is a discernible, key group of Leave voters who have changed their minds about Brexit. That much becomes clear if, as in the table below, we examine separately the current vote intentions of those who voted Remain in 2016 and those who backed Leave. In both cases over 85% say they would vote exactly the same way as they did in 2016. The sound and fury of the last three years has left the vast majority of voters unmoved. And although 8% of those who backed Leave say that they would now vote Remain, they are counterbalanced by 8% of Remain supporters who indicate that they would now support Leave.

The principal reason why public opinion is now tilted towards Remain is because, as we have noted before, those who did not vote three years ago prefer Remain to Leave by around two to one (if they express a view at all). In part, at least, this reflects the fact that this group of abstainers consists disproportionately of younger voters who in general are more likely to back Remain. However, it also suggests that, far from being certain to produce a majority for Remain, the outcome of a second referendum could turn on the ability or otherwise of the Remain side to mobilise the support of a group of voters who cannot necessarily be relied upon to vote at all.

Meanwhile, we should note that, in so far as there has been any change in recent weeks, it consists of a slight narrowing of the lead for Remain. The latest figures of Remain 52%, Leave 48%, contrast with ones of Remain 54%, Leave 46%, that had hitherto pertained for most of the time since the beginning of this year. Still, this movement could be the product of chance variation or the possibility that more recent polls have been undertaken disproportionately by companies that tend to produce relatively narrow leads for Remain anyway.

However, this seems to be an inadequate explanation. Of the four companies that have polled vote intentions in a second referendum since the beginning of May and who also did so in January this year, three (BMG, Survation and YouGov) have registered clear drops in support for Remain, on average by three points, while only one (Kantar) has not.

The principal explanation for this change appears to be that there has been some ‘hardening’ of the Leave vote in recent weeks. At the beginning of the year we reported that while 89% of those who voted Remain said that they would vote the same way again, the equivalent figure among Leave supporters, 83%, had become somewhat lower. Now the two figures are almost identical. Recent events have, it seems, simply reinforced Leave voters in their original views rather than encouraged them to think again.