A 25% increase in the number of individuals having no religion in 2011 had seen a rise of 48.5% in 2014 according to surveys.

According to a new analysis by the Scottish Social Attitudes survey, about 52 per cent of the population said they were not religious in Scotland or Northern Ireland.

An analysis in England and Wales revealed that the “nones” have reached about a 48.5% increase in 2014. Anglican Christians, Catholics and people of other faith made about 43.8% of the population.

“The striking thing is the clear sense of the growth of ‘no religion’ as a proportion of the population,” said Stephen Bullivant, senior lecturer in theology and ethics at St Mary’s Catholic University in Twickenham, who analysed data collected through British Social Attitudes surveys over three decades.

“The main driver is people who were brought up with some religion now saying they have no religion. What we’re seeing is an acceleration in the numbers of people not only not practising their faith on a regular basis, but not even ticking the box. The reason for that is the big question in the sociology of religion.”

The analysis is expected to fuel concern among Christian leaders. The growing numbers of non-believers had caused the Church of England’s attendance to fall for another 30 years.

Millenials who are particularly critical of faith institutions. Many of them, Anglican-raised, had abandoned their faith. “Cradle Catholics” who keep the legality of their faith but abandon their belief had increased in number.

The vast majority of converts come from other Christian denominations, rather than non-Christians or people with no religion. “There’s a kind of denominational musical chairs,” said Bullivant. “No one is making serious inroads into the non-Christian population.”