The Catholic population in Northern Ireland is now just three percentage points behind the number of Protestants in the province.
New census figures show that the gap between the proportion of Protestants and Catholics has narrowed.
The percentage of Catholics is up to 45 per cent while Protestant representation has fallen to 48 per cent from the 2001 census.
Experts say the dwindling gap between the two groups will lead to major political change in the near future.
When first created the Northern state had a 66 per cent to 33 per cent Protestant population over Catholic and Sir James Craig called it a “Protestant state for a Protestant people.”
The new figures are detailed in the 2011 census, published on Tuesday by the Northern Ireland Statistics and Research Agency.
The new census shows that almost half the population, 48 per cent, designated themselves as British when asked to select one or more of a number of identities, including Northern Irish or Irish.
The report also states that a total of 29 per cent of the overall population included Northern Irish as an identity while 28 per cent included Irish.
The 2011 census was the first time a question on national identity was asked in Northern Ireland.
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The results show that 40 per cent said they were British only with the remaining 8 per cent opting for British along with another one of the identities, such as British and Irish or British and Northern Irish.
A quarter of the population defined themselves as Irish only while 21 per cent said they were Northern Irish only.
Questioned about their religion in 2001 in the last census 53 per cent of the population replied Protestant with 44 per cent Catholic.
The Irish Times reports that statistics from the North’s Department of Education for 2010/11 showed 120,415 Protestants and 163,693 Catholics in schools, equating to 57.6 per cent Catholic and 42.4 per cent Protestant pupils.
An additional 37,609 classify themselves as ‘other Christian’ (8,282), ‘non-Christian’ (1,726) and the 27,601 who fall into the ‘other/no religion/religion not recorded’ category.
The paper states that figures for 2009/10 show that in Queen’s University, Belfast, there were 8,710 Northern Ireland-domiciled students of a Catholic background compared with 6,740 from the Protestant tradition.
In the University of Ulster there were 11,070 Catholics and 7,020 Protestants.
In the two teacher-training colleges, Stranmillis and St Mary’s, there were 1,215 Catholics and 650 Protestants.
The Northern Ireland population now stands at 1,810,900, the highest ever recorded, and brings the population of the island of Ireland to just under 6.4 million which is the highest population in Ireland since the first post-Faminecensus of 1851.
The population on the island of Ireland has increased by more than 1.25 million in the past 21 years and by well over two million in the past 51 years.