A Traveller and Roma representative organisation says Irish venues should 'reconsider' hosting British comedian Jimmy Carr.
In a recent stand-up routine for Netflix, Carr joked about the horror of "six million Jewish lives being lost to the Nazi war machine" - before suggesting the deaths of "thousands of Gypsies" had been one of "the positives" of the Holocaust.
Martin Collins is co-director of Pavee Point. He told Newstalk Breakfast a line was crossed.
"These comments from Jimmy Carr go beyond racism, he actually glorifies genocide.
"Let's remember: a minimum of 500,000 Roma Gypsies were persecuted by the Nazis during the Second World War - men, women and children.
"And then this guy takes to the stage, and he begins to trivialise and make fun of this terrible genocide.
"So he is, in effect, glorifying genocide which is extremely dangerous and concerning."
Carr is due to play several dates around Ireland later this year - including Dublin, Cork, Galway, Killarney, Sligo, Letterkenny and Wexford.
But Mr Collins says venues should consider dropping him.
"We understand he will be doing a number of live shows in Dublin in May.
"I'm asking the promoters and the owners of these venues to reconsider hosting Jimmy Carr.
"This was a case of blatant racism... and in advance of the show, he actually said 'This is a career-ending joke'.
"So he was deliberately courting publicity and controversy".
And Mr Collins says free speech must be tempered with protecting the vulnerable.
"I do think there has to be some sanction; I'm not suggesting for one moment that the guy's career would end.
"But certainly I think a number of shows should be cancelled so we send out a very clear, unequivocal message that this sort of racism and glorifying genocide in any platform is just not acceptable.
"There has to be a balance between free speech, and protecting vulnerable communities from being further victims of racism".
