He also said Irish-Americans are not receptive to being 'shaken down' for money. But his criticisms were rejected by the Minister for Tourism Leo Varadkar, also speaking on Today FM, who defended The Gathering.
Gabriel Byrne said Taoiseach Enda Kenny's speech launching The Gathering was 'offensive’.
"People are sick to death of being asked to help out in what they regard as a scam.
"I wish The Gathering the very best of luck but they have to understand that the bridge between the Diaspora and the people is broken and I tried to fix that for two years and it’s still broken.
"Most people don’t give a shit about The Diaspora except to shake them down for a few quid.
"The Diaspora has a very powerful spiritual connection to the Island of Ireland.
"I remember when I was growing up in Dublin those buses would pull up and those people in Burberry coats would be laughed at because they’d say 'here come the yanks looking for their roots'.
"Well, as far as I’m concerned one of the most sacred things you can do is look for your roots.
"If your grandfather left during the Famine that’s a very sacred journey that you make back there but we laughed at it.
"The other day I was talking to a group of people. One of them was an illegal immigrant. His father died, he couldn’t get home. He feels abandoned by the Irish Government. He feels an alien. He can’t go back.
"Then I talked to two kids, a girl and a boy who were forced to emigrate because there are no jobs. And they blame the incompetence and the 'gangsterism' of the government for being forced to emigrate."
Byrne stepped down as Ireland’s cultural ambassador at the end of 2011.
"It was a tremendous achievement what we did in two years. I was really disappointed the way all those contacts, all that hard work was just dropped and it really made me disillusioned and disappointed with this Government who go on about their love for culture for arts and actually really don’t give a toss about it."
But Mr Speaking on The Last Word on Today FM (where Byrne had also made his criticisms yesterday) Varadkar reacted to Bryne's labeling of The Gathering as a 'scam'.
Mr Varadkar said: "I don't think that's true. He's obviously a very popular figure—particularly popular with women of a certain age group—and he did a very good job as Cultural Ambassador, but I don't think what he said was true.
"The response I've been getting to The Gathering has been really great in America, Britain, Europe and at home here in Ireland."
He went on to say: "I thought the commentabout the Burberries was particularly strange. Gabriel Byrne was saying that he used to laugh at the Americans when they arrived as tourists—that's not what happens… There were over 30,000 Americans in Dublin for the recent match , they got a huge reception, people were delighted to have them around the city, and you just think of all the Americans who go to Killarney and Westport every year and they're made feel so welcome. In fact, they're made feel so welcome that this year may even be a record year in terms of the number of Americans visiting Ireland.
"At the moment there are now 1,000 'Gatherings' confirmed and these are peoples, communities, families, organizations all over Ireland who are dipping in to their own pockets and organizing events to welcome people to Ireland. Bear in mind The Gathering isn't just about people from the diaspora and emigrants, it's really for anyone who has an interest or love of Ireland and our culture."