A Fox News host has commented on comments made earlier this week by actor Jeremy Irons, who linked incest to equal marriage, and suggested that supporters of equal marriage will move on to push for polygamous marriage next.

Irons, 64, made the comments to the Huffington Post’s TV channel earlier this week. “Could a father not marry his son?” Irons asked host Josh Zepps.

When reminded about laws preventing incest, the Oscar-winner replied: “It’s not incest between men”, because “incest is there to protect us from inbreeding, but men don’t breed.”

Erick Erickson, a contributor to Fox News, and a political blogger posted on his own blog RedState, commenting on what Irons said, and asked why not legalise incest, if the US is to legalise equal marriage.

He wrote: “Seriously. Why not incest… If love and commitment are the justification for marriage, why exempt this?

“So why not fathers marrying sons and moms marrying daughters? Is it because of the “ick” factor? Why should that preclude it?”

He continued: “If life comes down to who you love and who loves you back, if a father and son love each other so much they want to get married, there is little moral difference between two people of the same sex getting married who are not related and want to be and two people of the same sex who already are related becoming closer.”

The blogger went on to claim that, if equal marriage becomes legal, advocates of equal marriage will switch to support polygamous marriage.

“The truth is, many, many, many of the same people who are now in support of gay marriage, but would oppose this or polygamy will, once the next step is advanced, support these things too. They just have to lie about it for now until they can shift public opinion further.”

Political satirist Stephen Colbert mocked the Oscar winning actor for his comments earlier this week , joking “what’s to stop a man from dressing up as a woman to get equal pay. I mean insurance wise, it’s a nightmare.”

Alan Cumming, 48, who entered into a civil partnership with his husband in London in 2007 and then married him in New York last year, also criticsed Irons for the comments, tweeting: “I hate when people say they don’t have strong feelings about something then proceed to spew offensive and ignorant ones. Jeremy Irons.”

Ruth Hunt from gay rights charity Stonewall branded the actor’s remarks “bizarre” and referenced his role as a corrupt Pope in TV show The Borgias. She said: “Few people will agree with Jeremy Irons’ bizarre ‘concerns’ about equal marriage. Sadly his comments do seem to indicate he’s taken his role as a Pope in The Borgias a little too seriously.”

Meanwhile, journalist and LGBT campaigner Patrick Strudwick tweeted: “Jeremy Irons thinks gay marriage would ‘debase’ it and lead to fathers marrying their sons. Cretin.”