Cindy McCain, the wife of former GOP presidential nominee Senator John McCain, has said she thinks there will be a “major turn”, and that both major parties will support equal marriage by the next US presidential election.

Mrs McCain told the Wrap on Monday that she thought the two major US parties will no longer be divided on the issue by the time the next election comes around.

“You’re going to see a major turn,” she said. “By the next presidential election I think this will be an issue that will be very much agreed on by both parties.”

She was recently honoured with the Trevor Hero Award at an annual fundraiser for the Trevor Project in New York City.

Attending the event, she represented the wing of the GOP which believes that support for equal marriage is growing, and that opposing it will soon become untenable to continue to oppose it.

Her husband, John McCain, does not share her stance on equal marriage.

Senator McCain said in March that he didn’t think he would be following the lead of fellow Republican Senator Rob Portman, who stunned so many when he announced his support for equal marriage.

Mr Portman said he had changed his views after realising that his 21-year-old son, Will, was gay.

“I respect anyone else’s decision and we all learn in life and grow and mature,” he said recently in an interview with TheHill. “I have changed my position on other issues in my life, but on this one, I had not contemplated changing my position.”

Mrs McCain, however, said she thinks that her husband will eventually change his mind on the issue.

“He hears from his own daughters and his own children and from me a little bit about this,” she said. “But it’s also okay to disagree, but do it in a manner that’s respectful.”

“We have different views,” She continued. “We have raucous dinner table conversations and we encourage that. In fact you have to be tough to survive at our table.”