Conor Lenihan has "no business" being science minister if he supports the views of a controversial anti-evolution book, according to one of the world's foremost critics of organised religion.

In an interview with the Sunday Tribune, Professor Richard Dawkins said Lenihan had committed "an act of irresponsibility" by lending his support to the launch of The Origin of Specious Nonsense last week. He also rounded on its author John May, a reputed friend and constituent of Lenihan, whom he referred to as an "idiot" and an "ignoramus" for his views on evolution.

Lenihan was forced to step back from playing a central role in last Wednesday's launch at the insistence of May, who said he was "embarrassed" at how the minister was being treated over the affair.

The controversy surrounding the launch, and Lenihan's proposed involvement, was due to his position as science minister.

"If Mr Lenihan is indeed a creationist or an anti-evolutionist then he has no business… in my opinion, he should not be a minister for science," said Dawkins.

"Obviously evolutionary science is at the centre of biological science; you can't do biological science without evolutionary science, so if he is hostile to one of the central ideas of biological science then he has no business being a minister for science.

"I am not a political analyst and I am not Irish but I think that a government minister – although they are entitled to have their own opinion – if they express opinions that are controversial they will be taken more seriously."

He said Lenihan had carried out "an act of irresponsibility" by giving May a platform and that by subsequently pulling out, he had furthered the publicity.

Dawkins, a celebrity atheist, former Oxford professor and renowned author, has produced several television documentaries and is known for his open disdain towards the 'intelligent design' theory of life.

Dismissing the book and its author, he continued: "I listened to a YouTube film of May making a little speech about his book and I thought what a complete ignoramus, what an idiot!

"Doesn't he know anything? And the answer is no, he doesn't. I would not normally be shocked about that because there are many idiots about but I was shocked that Mr Lenihan would be launching [May's book]."

May, the self-described "sworn enemy of evolutionists", has previously criticised Dawkins.

In an online posting he said of his writing on evolution: "I kid you not. Richard Dawkins, a professor in Oxford who has more awards to his name than Muhammad Ali; he believes this and he wants you to believe this nonsense. Nonsense!"

While the evolution debate rages in the US between the scientific community and fundamentalist Christians, Dawkins believes Islam posts more of a threat to Europe than creationism and insists religion here is on the wane.

"Two things on Ireland: first, the official position of the Roman Catholic church is in favour of evolution and that needs to be more widely known," he said.

"Secondly, I am not sure how religious Ireland really is nowadays. I know there is quite a massive attrition of new priests coming along. I am seriously hopeful that the Catholic church is dying in Ireland."