British Prime Minister David Cameron was thanked for his support of gay marriage as President Barack Obama looked on.

The incident occurred last month during the White House's state dinner for Cameron, The Washington Post reported.

“Mr. Prime Minister, thank you for all that you're doing for marriage equality in Great Britain,” one guest told Cameron as he stood next to Obama in the Blue Room.

“It takes a conservative to convince a liberal about gay marriage,” Cameron replied with “a gesture towards the president.”

The British government last month released a consultation document detailing its plans to make gay marriage legal before 2015. Britain currently recognizes gay couples with civil partnerships.

The plan has the backing of Cameron, who recently said: “I don't support gay marriage despite being a Conservative. I support gay marriage because I am a Conservative.”

This week, he attempted to reassure Christian conservatives who oppose gay marriage, stressing that churches would not be required to perform unions that violate their faiths.

The proposal would “change what happens in a register office, not what happens in a church,” he said.