Hirst's Away From the Flock: "Disgusting"

But Mr Hirst, famous for works such as Mother and Child Divided, a cross-section of a dead cow, and Away from the Flock, a lamb in formaldehyde, said Mr Guiliani should find out more about art before he criticised.

"It sounds like it's election year to me," he told BBC Radio 4's Today programme.

"I think you need to find out a lot more about what's going on, I don't think you can walk in there and say it's all rubbish and needs to be cancelled.

"There's a lot of artists in that exhibition," he said. "Most of the work is over 10 years old and it is important."

Giuliani: Should "grow up"

Mr Guiliani had particularly objected to Turner Prize winner Chris Ofili's painting The Holy Virgin Mary, which incorporates his trademark elephant dung.

Catholic Mr Guiliani had accused the artist of "desecrating somebody else's religion".

But Mr Hirst, also a Catholic, said that the use of the dung was simply a nod to the early tools of artists.

"In the beginning, people were painting on cave walls using dung before they were using anything else. I think it's just revisiting that," he said.

'Animal abuse'

The exhibition also came in for criticism from animal rights charity Peta (People For the Ethical Treatment of Animals), which said it was "disgusted and dismayed" by Mr Hirst's presence in the art world.

Ofili: Desecrating someone else's religion?

"We think Mr Hirst glorifies animal abuse," a spokesman told the Today programme. "We think his artwork is more of a crime scene.

"On the plus side, he probably makes a lot of people vegetarian by showing them what dead animals look like."

Mr Hirst said he believed the animal rights groups were more interested in publicity for themselves than in statements he was trying to make.

"You walk past any butcher's and it's full of cows and pigs and sheep, and then you suddenly take one out of that context, and it's bought from exactly the same place, and you're making a statement in a way against it," he said.

"You're trying to put the personality back into the animals and all of a sudden everybody's up in arms.

"They should be picketing the local butcher's."

Free speech issue

Mr Hirst admitted he was concerned about the threat to the exhibition.

"If it's serious, it's outrageous," he said. "It boils down to freedom of speech.

"There's a visual language that exists. There's things you can and things you can't do, and we're constantly making laws and rules, and artists work within that."

Asked if he had any final message for Mr Guiliani, he said: "Grow up".