In 2016, the UK voted by a small majority, 52% to 48%, to leave the EU. The latest poll tracking voting intentions, conducted by We Think, showed that if a second referendum were held now, the result would be a resounding vote to rejoin the EU, by a massive majority of 63% to 37%. Yet other surveys have found that relatively few people have changed their minds. The proportion who would vote differently is higher for leave voters (16%) than remain voters (6%), but this would shift the dial by only 5%, from a 52:48% leave majority to a 53:47% rejoin majority. Why such a discrepancy?
The other 10% of the swing to rejoin since 2016 is explained by demographic changes. Older people, who took part in the referendum and who predominantly voted for Brexit, are dying, while young people, who are predominantly rejoiners, are entering the electorate.
Let’s look at the numbers.
Loss of older Brexit supporters
In 2022, a total of 577,160 deaths were recorded in England and Wales, 62,942 in Scotland, and 17,162 in Northern Ireland, amounting, in total, to a little over 657,000 deaths across the UK.
Just under 396,000 of those deaths in England and Wales, so an estimated 451,000 deaths across the UK, were of people over the age of 75. If we return to the poll and click on the ‘Age’ tab on the left, we can see that if a second referendum were held now, the over-75s would vote to stay out of the EU by 75% to 25%, a difference of 50%.
So those deaths amount to a net loss of over 225,400 Brexit supporters. A further approximately 113,000 deaths in the UK of people between the ages of 65 and 74, who would vote to stay out by a majority of 54% to 46%, adds 8,374 to that total. In all, the deaths of people above the age of 65 result in an annual net loss of almost 234,000 Brexit supporters.
Gain of younger rejoiners
In 2020, there were 717,252 18-year-olds in the UK. Young people, in the 18-25 age range, would vote to rejoin the EU by a massive majority of 88% to 12%, a difference of 76%, resulting in a net annual gain of over 545,000 rejoiners. This figure is calculated on the assumption that the rejoin vote is constant across the 18–25 age range. But as rejoin sentiment decreases almost linearly with age, by around 0.8% per year, it is likely that the proportion of 18-year-olds supporting rejoin is actually in excess of 90%.
Taken together, these two sets of demographic changes amount to an estimated annual increase of over 779,000 in support for rejoin, assuming a constant 88% support between the ages of 18 and 24, and over 807,600 assuming a 90% figure for 18-year-olds.
Estimating the rate of demographic change
At the 2021 census, the adult (18+) population of England was almost 45 million. As England accounts for some 84% of the UK population, we can estimate the adult UK population to be just over 53 million. An 807,000 annual increase in support for rejoining the EU is equivalent to 1.52% of the adult population.
However, these calculations are based on the whole UK population, whereas the baseline of 63% for rejoin vs. 37% for stay out, as reported in the We Think poll, excludes don’t knows and non-voters. Moreover, the calculations do not take into account the issue of differential turn-out in elections, which has typically been higher among older people. For comparability, the estimates of demographic change need to be adjusted to reflect the voting population. The turn-out figures from the 2016 referendum provide the most pertinent source of information.
According to a survey conducted shortly after the referendum, the proportion of the population actually voting was 48% of the 18–24 age range and 70% of over 75s. Applying these weightings to the population figures, so as to reflect the proportions actually voting, reduces the estimate of young (18) rejoiners gained to 275,400 and the estimate of older (65+) Brexit supporters lost to 163,600, a net rejoin gain of a little over 439,000. Relating this figure to the referendum voting population of 33.5 million gives a slightly lower figure for the rate of demographic change of 1.31% per annum.
An inexorable shift towards rejoining the EU
Added to the current estimate of 63% for rejoin, this would mean that, as a result of demographic changes, the potential rejoin vote may be close to 65% by the time of the coming general election, at 71% at the end of the next five-year parliamentary term, and at 77% after two five-year parliaments.
These figures are based on a particularly rejoin-friendly starting point: other polls have rejoin in the lead by narrower margins. They may also be over-estimated because the demographic effect among older voters is likely to decay over time, as fewer of them will have voted to leave. However, the growth in support for rejoin described here results solely from the inexorable demographic changes, and takes no account of a likely increase in Bregret as leave voters come to accept that Brexit was a catastrophic mistake.
Moreover, it has been reported that the Labour party is giving serious consideration to lowering the voting age to 16, which, without going into the details, would increase the rejoin vote by a further 2%. Extending the vote to EU citizens – also under consideration by Labour – would add a further 2–3%.
Even if they are out by a few percentage points, these estimates of support for rejoin are too high for governments to ignore. Absent convulsive changes in the make-up of the UK electorate, it appears inevitable that the UK will be seeking to rejoin the EU in the second term of an incoming Labour government.
