Sinn Fein has called for preparations for an Irish reunification referendum after a census showed Catholics outnumber Protestants in Northern Ireland for the first time in the country’s history.
During partition in 1921, Northern Ireland’s borders were drawn to ensure a Protestant majority. Unionists are traditionally Protestant, while historically nationalists are mostly Catholic.
However, in the census, taken last year, a total of 45.7 per cent of the 1.9 million population identified as Catholic, compared to 43.5 per cent who were Protestant.
There was also a drop in the number of people in Northern Ireland who saw themselves as British and an increase in those identifying as Irish compared to the last census in 2011.
The 2011 census recorded 48 per cent of the population as Protestant or raised Protestant, and 45 per cent as Catholic.
Sinn Fein’s Michelle O’Neill, Northern Ireland’s First Minister designate, said the change was “historic”.
John Finucane, a Sinn Fein MP, said: “The Irish government should establish a Citizens’ Assembly to plan for the possibility of a unity referendum”. He described the shift as “irreversible”.
Philp Brett, a DUP Member of the Legislative Assembly, told BBC Radio Ulster: “I don’t come from a traditional Protestant background but my support for the Union isn’t in question.
“What most worries me is an attempt by some to try to use a census [...] as some sort of mini-referendum on the position of Northern Ireland within the UK.”
Dr David Marshall, of the Northern Ireland Statistics and Research Agency, said the Catholic community was on average younger than the Protestant one.
He said there were more births than deaths in the Catholic population, which increased its size, and more deaths than births in the older Protestant population.
“There are other factors as well, but those are the two key things,” said Dr Marshall. He said there was a “fair chance” that increasing numbers of Protestants were describing themselves as having no religion.
In May, Sinn Fein became the biggest party in Northern Ireland for the first time, overturning an unbroken stretch of unionist, Protestant majorities.
However, neither community has a majority and there is no guarantee that a voter would vote for or against reunification in a referendum just because of their religion.
While Sinn Fein won the elections, there was a majority in favour of unionist parties but support was fractured among them. More and more people no longer define themselves as unionist or nationalist.
In the census, 17.4 per cent of the population said they had no religion – a 7.3 per cent increase from 2011 – while the centrist Alliance Party, which is neither unionist or nationalist, got its best ever results in May’s elections.
The census included a question on people’s sense of national identity. 31.9 per cent said they were “British only” and eight per cent deemed themselves “British and Northern Irish”.
The proportion of the population that said they were “Irish only” was 29.1 per cent, while for those identifying as “Northern Irish only” it was 19.8 per cent.
In the 2011 census, 40 per cent said they had a British-only national identity, 25 per cent said they had an Irish-only identity and 21 per cent viewed their identity as being only Northern Irish.
The Good Friday Agreement recognised the right of people on the island of Ireland to reunify if border polls in Ireland and Northern Ireland support it.
UK law says the Secretary of State for Northern Ireland should order a vote if it “appears likely” a majority of voters want a united Ireland, but is unclear on how that should be decided. The Irish government must also agree.
Brexit, which most Northern Irish voters opposed, and the Northern Ireland Protocol, which created the Irish Sea border with Britain, have thrown the spotlight on questions of national identity.
The census also showed a 63.5 per cent increase in the number of people in Northern Ireland who hold an Irish passport. The number rose from 375,800 in 2011 to 614,300 in 2021, probably in order to retain EU rights lost after Brexit.
Northern Ireland has been without a fully functioning government since February and, in a sign of continued divides, the DUP is boycotting the restoration of Stormont over the protocol.