Demography isn’t destiny but it contributes powerfully to it. This week’s Northern Ireland 2021 Census release, showing Catholics outnumbering Protestants for the first time, does not in itself doom the Union. It should, however, represent a major warning to Unionists on both sides of the Irish Sea.

That is because the Union now depends on the votes of Catholics and liberal-Left Protestants who backed Remain in overwhelming numbers. These people do not have a strong British identity, but it is coming under more strain in a region where the Northern Ireland Protocol means Brexit is still a live issue.

DUP politicians often score points with their own base by trampling on the shibboleths of these voters, while few London-based Tories understand what makes them tick at all. That isn’t a good platform from which to win their votes in a border poll. From here, I’d be surprised if the Union makes it to 2040.  

According to the census, the proportion of people from a ‘Protestant background’ fell from 48% in 2011 to 43% last year while the proportion from Catholic backgrounds rose slightly from 45% to 46%. Religion and national identity are not always the same thing in Northern Ireland — there are Catholic Unionists and Protestant Nationalists. But the proportion of those identifying as British also fell, identically, from 48% to 43% in the same censuses. Locked-in demographic trends mean those Protestant and British figures will continue to decline as the years go on.

Many people expected a Brexit effect, with some Remainers who had hitherto identified as British opting for an Irish or Northern Irish identity, but this has not been borne out by the data. The figures instead indicate that the liberals from Protestant backgrounds who helped deliver the region’s 56% vote for Remain had already identified as Irish or Northern Irish rather than British.

These detribalised liberal Protestants are a significant part of the swing vote that will decide any border poll, along with ‘soft’ Nationalists who were traditionally more interested in civil rights and cultural recognition than constitutional change. These groups overwhelmingly support the staunchly pro-EU Alliance Party and SDLP, backed Remain by massive margins, and have been royally angered by Brexit. 

Northern Ireland’s Assembly in May delivered a 53-37 majority for pro-Protocol parties, and these voters are rather wound up by the DUP and UK attempts to renegotiate it, which they fear may leave the region at ground zero of a UK-EU trade war. Common sense might dictate quietly allowing the Protocol to become the new normal, and this key slice of the electorate could then get back to worrying about rare vinyls and new IPAs rather than economic armageddon. 

Unionists have long consoled themselves with the myth of the ‘garden centre Prod’ — a hundred thousand voters in Greater Belfast who sat out normal elections, repelled by Unionism’s political style, but who were resolutely British and would turn out en masse in any border poll. Elections since 2016 have instead shown these voters have a complex identity and are mainly socially liberal and pro-European. 

One must also note that there is no obvious pathway to a border poll from here, and the Nationalist vote has also shrunk slightly in recent years due to the Alliance surge. But at some point, a UK general election result will make the SNP kingmakers just as their IPP antecedents were in the decades before the First World War. Then Unionism would face an existential referendum with barely two in five votes safely in the bag, and the swing voters mostly people whom they don’t comprehend. 

There is a fundamental lack of cultural literacy about Northern Nationalists and ‘nationally-minded’ liberals among Tory politicians and commentators. Few seem to understand, for example, why the failure to install Michelle O’Neill as First Minister after Sinn Féin’s first place in May’s elections is a totemic issue even for many who frankly despise her party. Unthinking Telegraph editorials are easily weaponised by the Derry set. Interestingly, however, King Charles seems to ‘get it’. 

The Union is certainly defendable, but with a shrinking minority of Northern Ireland people identifying instinctively with Britishness, doing so will take more imagination and empathy than the DUP or English Tories have shown so far.