The number of atheists in Ireland has shot up by nearly three quarters whilst the number of Catholics has dived, according to the latest census figures.

In 2011 a total of 277,237 ticked the ‘no religion’ box on the census form, but five years later 481,388 did so.

That means that atheism is now the second largest belief system in the Irish Republic accounting for 10.1% of the population.

The news was welcomed by the pressure group Atheist Ireland which said, "We are increasingly optimistic that a secular Ireland is inevitable, free of religious privilege and religious discrimination against any citizens."

Meanwhile, the socially conservative Iona Institute directed followers to a lecture by Dr Stephen Bullivant of St Mary’s University in London which underlined what he called, "The (still!) exceptional religiosity in Ireland." 

For the first time ever the percentage of Catholics in the Republic has dipped below 80%; last year 78% said they were Roman Catholic, down from 84% in 2011 and 93% ten years ago.

Read More: Diverse Muslim population growing in Ireland

The figures, however, varied widely across the country. Midlands county Offaly was the most Catholic part of the country with 88.6% happy to describe themselves as Catholics. By contrast, in leafy Dún Laoghaire-Rathdown, County Dublin only 69.9% considered themselves Catholics.

Other Christian denominations, however, showed big increases in the number of followers: 126,414 people said they were members of the Church of Ireland, a 2% increase on the 2011 figures, and 62,187 said they were Orthodox Christians – a 37.% increase, mostly due to extension of the EU’s freedom of movement rules to Romanian citizens in 2014.

There are also rising numbers of Jews and Muslims. There are now 2,557 Jews, a 28.9% increase on five years ago, whilst the number of Muslims in Ireland has close to doubled over the past ten years. In 2006 there were only 32,500 Muslims in Ireland, now there are 63,443 – more than 40% of whom live in Dublin.

Read More: Vanishing tribe – Ireland's Jewish community fades further each year

"Percentage of Catholics in the Republic has dipped below 80%"iStock