US Senator Rob Portman, who came out in support of equal marriage last week, spoke at a Republican Party event this weekend, and said that the audience was “very respectful” of his change in stance.

Senator Portman who was among the original sponsors of the Defense of Marriage Act (DOMA) announced that he has changed his anti-equal marriage stance, following the personal revelation of his own son’s coming out as gay.

Addressing reporters at the GOP’s Lincoln Day Dinner, he said that the audience at the event were a “split group”, but were “very respectful” of his newfound support for equal marriage.

Of his son, Will Portman, he said: “We support him and love him.”

He was greeted with a standing ovation when he took to the stage, and rather than addressing the equal marriage controversy, he spoke of the Republican Party as a whole, which he said needed to “change direction”.

The Ohio Republican previously rumoured to be in the running for Vice President during Mitt Romney’s 2012 campaign, told CNN he had been deliberating on the issue since his son came out to him as gay two years ago.

When asked at the Lincoln Day Dinner whether he thought his pro-gay stance had played a role in not running for Vice President, he said the decision was made before the announcement he was pro-gay and “not a factor”.

In 1996 Portman was one of the co-sponsors of DOMA, which federally defined marriage as being between a man and a woman.

The Supreme Court will later this month consider an appeal against Act, urged on by President Obama and even Bill Clinton, the former President who signed DOMA into US law.

As well as the appeal on DOMA this month, the Supreme Court will also consider overturning Proposition 8, which bans same-sex marriage in California.

Already, Portman has drawn criticism from religious groups who previously supported him, as Phil Burress of the Ohio group Citizens for Community Values, spoke out to say that he thought Portman was “a very troubled man”, and suggested that he was “distraught” over his son coming out.

In an interview, the United States House Speaker John Boehner said that he “can’t imagine” he would “ever” change from his current stance in opposition to equal marriage.