Former US presidential hopeful Rick Santorum has spoken out against the idea that the Republican Party might support equal marriage, and said it would be “suicidal” if it did.

Santorum, a former US Senator, made a comparison between two Republican Senators who have recently come out in support of equal marriage, and Republican Senators who supported abortions in the 1960s.

Mark Kirk of Illinois became the second Republican Senator to come out in support of equal marriage last week, and followed Rob Portman, one of the original sponsors of the Defense of Marriage Act, who also recently offered his support to same-sex marriage after the revelation that his own son was gay.

Speaking in an interview with the Des Moines Register, Santorum cast doubt on whether the GOP will support equal marriage.

He said: “I’m sure you could go back and read stories, oh, you know, ‘The Republican Party’s going to change. This is the future.’ Obviously, that didn’t happen.”

“I think you’re going to see the same stories written now, and it’s not going to happen. The Republican Party’s not going to change on this issue. In my opinion, it would be suicidal if it did.”

He also went on to claim that “[marriage equality] is not a well thought-out position by the American public,” and said that Americans had not thought enough about the implications on legalising equal marriage.

Santorum, who has been rumoured to be gearing up to make another run for US President in 2016, also commented on the US Supreme Court’s recent hearings on two cases around equal marriage bans.

“I think you’ll see, hopefully, a chastened Supreme Court is not going to make the same mistake in the cases as they did in Roe v. Wade,” he said.

“I’m hopeful the Supreme Court learned its lesson about trying to predict where the American public is going on issues and trying to find rights in the Constitution that sit with the fancy of the day.”

The Supreme Court Justices two weeks ago indicated a possible interest in striking down the Defense of Marriage Act (DOMA), as it heard arguments around the issue.

This was the second day of hearings, as Tuesday the court heard arguments around Proposition 8, the state of California’s ban on equal marriage. Then the justices questioned the meaning of marriage, and challenged arguments for the ban. 

A recent poll released late last week, found that, over the past eight years, support for equal marriage had grown in all 50 US states by an average of 13.6%.

In March, a survey conducted in the US revealed support for same-sex marriage had grown overall to be a “mirror image” of ten years ago, with the majority now in favour of legalisation and many calling for a nationwide law.

The poll found that 58% of Americans now support the legalisation of same-sex marriage, while 36% oppose it.

A new poll by an anti-LGBT rights Christian campaign group LifeWay, also in March found that a clear majority of Americans, particularly younger people, supported gay rights.