One of Mitt Romney’s key aids has spoken out in support of same-sex marriage, saying that the Republican Party needs to adapt its policy to suit more modern views.

David Kochel, Romney’s Iowa Strategist, spoke at an event hosted by Iowa Republicans for Freedom, a group that backs same-sex marriage.

“Support for the freedom to marry is emerging as a mainstream position in the Republican Party. If we are to be the party of principles and values, isn’t our first obligation to the principle of freedom, and the value of individual liberty?,” Mr Kochel asked the crowd.

“I think that our party generally has to think through how best to appeal to some new groups of voters,” he added. “We’ve got to start to modernize some of our views and positions.”

In a tweet on Monday Mr Kochel said he had supported same-sex marriage for “at least 12 years”. He said his views had evolved to support it because of personal anecdotes from friends and members of the public.

Mr Kochel spoke to the Huffington Post about visiting his son’s high school and being asked about same-sex marriage.

“I answered the questions very honestly,” he recalled. “Well, for me personally, I said, ‘I think that rights need to be extended to all people regardless of orientation.’ And several of the students started nodding their heads, and began to question why so many in my party don’t have this position.”

“[After class my son] said to me, ‘Dad, you know I have friends whose parents are gay, and I just don’t see anything wrong with it, and nobody I know sees anything wrong with it.’”

“The Republicans have begun, painfully and grudgingly, to follow public opinion on this issue,” said Andrew Koppelman, a political science professor at Northwestern University.

“Their ultimate capitulation on this, as with immigration, is probably inevitable. And this is good news. The whole point of democracy is that politicians have to tailor their positions to follow the will of the public. It will be interesting to see how Republicans divide on this issue in the next presidential primaries. I’d be surprised if they are as united as they were last time.”

Bob Vander Plaats of conservative Christian group The Family Leader was more critical of Mr Kochel, asking on his blog: “[I]s this really what politics is about? Are we really supposed to abandon the core values and principles that have served us well throughout civilization so we can win elections?”

Before the November 2012 elections, the Republican Party said they would run on a platform banning same-sex marriage.