Repblican presidential hopeful Rick Santorum used an appearance in Iowa on Monday night to rail against gay marriage.

The politician, who has a track record of anti-gay remarks, said at the Lyon County Republican dinner that gay rights campaigners were deliberately trying to undermine religion.

He said: “The reason the Left has gone after same-sex marriage is because it’s a two-fer.

“When you redefine marriage, you cheapen marriage. You make it into something less valuable, less special … [and] it is a sure bet that will undermine faith.”

The former US senator also attacked government assistance programmes and ended his speech by asking the audience: “Please join me in saving America.”

In 2003, Mr Santorum outraged gay rights campaigners when he compared homosexuality to incest and said people should not have a right to privacy with respect to sexual acts.

In an AP interview, he said: “[I have] a problem with homosexual acts, as I would with what I would consider to be acts outside of traditional heterosexual relationships . . . if the Supreme Court says that you have the right to consensual [gay] sex within your home, then you have the right to bigamy, you have the right to polygamy, you have the right to incest, you have the right to adultery.”