The 54-year-old and his co-host Susanna Reid were embroiled in a particularly venomous row with Dr Mike Davidson, who claimed to have been “cured” from homosexuality by prayer.
“I believe that people are not born gay,” he told the Good Morning Britain duo. “That they come into homosexual feelings, and that it is something that in some cases is reversible for people who want to make that the trajectory of their lives.
“It’s inconsistent with some people’s value systems and they want to be true to themselves. I think we’re here today because there’s clearly a population group who feel they are not comfortable with homosexual expression, and they want out of it.”
“You mean [it’s inconsistent with] your values,” Piers Morgan waded in. “Do you know what we call these people? We call them horrible little bigots in the modern world. Just bigoted people who actually talk complete claptrap and are in my view a malevolent and dangerous part of our society.
“What’s the matter with you? How can you think that nobody is born gay and they all get corrupted and can all be cured?”
Davidson now holds his own classes with hopes to avert others from gay feelings, but Morgan was unconvinced and demanded that the therapist proved that he was straight.
“I now have two children and have been with my wife for 35 years,” he said.
Morgan interrupted: “But you’ve had gay sex? How many times?”
“I’m not going to tell you,” the doctor stressed.
Davidson continued: “Why do we have to stick to a binary label system? I have two children, I have been with my wife for 35 years, I have left homosexual practices.”
“Shut up you old bigot,” Morgan snapped. “Sorry, but this is ridiculous.”
Julian Clary appeared on the show directly after Davidson, and admitted: “I was worried I was going to have to sit on the same seat as him but thankfully we’ve moved over here.”
He quipped: “I can think of a cure for his homophobic bigotry, it involves a saveloy!
“What he’s doing is dangerous. But [Piers], you gave him a run for his money. It’s a shame you had him on though, really. It’s a shame you gave him air time.”
Morgan later locked horns with writer Afua Hirsch, who claimed Nelson’s Column should be torn down because she claimed the British flag officer was a “white supremacist”.
Good Morning Britain airs weekdays at 6am on ITV.