Scottish actor Alan Cumming has criticised Jeremy Irons after he suggested equal marriage in Britain could lead to fathers marrying their sons in a bid to avoid inheritance tax.

Irons, 64, made the comments to the Huffington Post’s TV channel. “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.”

In response, 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, tweeted: “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.”