Brian Whiteside can barely keep up with the demand. In January and February - the time of year when loved-up couples start to plan their weddings - this humanist celebrant estimates that he has to tell six of them that he won't be available for their special day. That's six couples every single day.

"There has been a huge rise in the numbers of people seeking non-religious ceremonies in the past few years," he says. "I've scaled back a bit, but some of my colleagues would do 80 weddings a year. And the demand keeps going up."

Last year, the Humanist Association of Ireland officiated at 1,500 weddings. A further 6,500 were civil ceremonies. "There were 12,000 Catholic weddings last year," Whiteside said. "That's 53pc of all weddings. Just 10 years previously, in 2006, there were 16,000 Catholic weddings here - 73pc of the total. And the figures for 10 years before that again, in 1996, were overwhelmingly religious - just 6pc were non-religious. Today, that figure today could be as high as 44pc."

For Whiteside, such evidence points to the huge rise of atheism. "It's a sign of society growing up, of people deciding that they don't need to keep up the pretence of being religious when they felt no religious devotion."

The figures are borne out in the latest census. Some 468,421 people - roughly one in every 10 men, women and children in Ireland - indicated 'no religion'. It's a 73.6pc increase since 2011.

Michael Nugent, head of Atheist Ireland, says the figure is likely to be far greater. "We're asked a leading question: 'What is your religion?' It should be, 'Do you have a religion?' A lot of people put down the religion they had when they were children out of habit, and then you have the head of the house filling out the census and sometimes assuming that family members have a religion simply because they were baptised."

Nugent is hopeful that the wording will be changed for the 2021 census which, he says, "would truly reflect how many atheists there are in Ireland right now".

The atheist lobby has made its presence known over the past few weeks. First, there was the controversy surrounding the proposed move of the National Maternity Hospital to the St Vincent's Hospital campus, and to land owned by the Catholic nuns order, the Sisters of Charity.

Then, this week, there's been the contentious vote in the Dáil which would compel all TDs to stand for daily prayer and would insist that the Ceann Comhairle be the one to deliver it, irrespective of his or her views.

For John Hamill, such official secularisation can't come soon enough. "Ireland has changed enormously in the past 20 or 30 years and there's a huge cohort of people who do not believe in religion of any description."

He has been atheist for as long as he can remember. "People sometimes say to me, 'Are you angry with the Church? Is that why you don't believe?' It's nothing to do with that: I merely look at Catholicism - and any religion you could care to mention - and think, 'It's simply not true'. I just don't believe in a higher being or a God, call it what you will." Hamill is originally from Belfast but lives in Castleblaney, Co Monaghan, with his wife and four children. They attend the local Educate Together school and he says they are fortunate to have one nearby. "A lot of people feel they have to baptise their children in order to get them into school, because so many are Catholic-run, and I think that's the next big thing that has to be tackled.

"I'm not saying there shouldn't be religion. It should be a personal choice. I would be just as opposed to a school telling children there is no god. I want our kids to be able to make up their own minds."

It's a philosophy espoused by Helen O'Shea (pictured), a mother-of-five from Ardee, Co Louth. "I want my children to make up their own minds," she says. "I don't want to be dogmatic about what I do or don't believe. That sort of freedom was denied to many people of my generation. Growing up, it felt as though the Catholic Church held huge sway over the country."

O'Shea's upbringing was normal for the time, right down to the "obligatory uncle who was a priest", but she started asking questions. "I don't know if I ever believed it," she says, "and I was about 12 or 13 when I decided that I didn't want anything to do with it. The communion thing, I just couldn't get my head around, and I had a fundamental problem with the concept of confession."

Her first child, David, was born in 1990 and she had him baptised because she didn't believe there was much choice at the time, and because she thought it could be difficult to find a school that would enrol a non-christened child.

But none of her four subsequent children - all born much more recently - have been baptised. "The Ireland of the past 10 or 12 years is a very different place to what it was like in 1990," she says. "Societal norms have changed hugely and there are a huge number of people who have no religion. Their voices are being heard now. For too long, we had to keep silent."

But some believe old habits die hard. Hamill says an article he was commissioned to write about his atheism by a regional newspaper was pulled when the editor disliked his reference to the Virgin Mary as "a carpenter's wife", although as Hamill points out, such a description is to be found in the Bible.

For another non-believer, a self-described "virulent atheist", it's time to stop the politeness. "For years, we've had to kowtow and listen to celibate men in dresses telling us what to do when it comes to sex, abortion and so on," he says.

"Well, those days are now in the past and even those who say they have belief tend to pick and choose the parts that suits their lifestyle or agenda.

"Would it not be best to simply say, 'Look folks, it's all rubbish and your faith is simply down to a fear of death.' You want to think there's some other magical existence out there, but you're wrong."

Helen O'Shea sees the message as far less confrontational.

"I know some atheist parents mightn't want to tell their children that they don't believe heaven exists, but what my husband and I do is reinforce the fact that we get one life and we should make the very most of it."

Indo Review