Prime Minister John Key says he gave approval to National MP Maurice Williamson to appear on American talkshow Ellen because it was an opportunity to promote New Zealand as a tolerant, progressive country.
Mr Key said he was surprised by the global attention Mr Williamson had received for his speech in the House on gay marriage legislation last week, and jokingly described the MP as "our own little gay icon".
Mr Williamson was invited to appear on Ellen Degeneres' show after his contribution to the debate became a social media hit, but he was concerned that he would break ministerial rules because the trip would be paid for by the show's producers.
Asked what his reasoning was for allowing the trip, Mr Key said: "It would be hard to stop him."
He added: "While he gave a very humorous sort of speech, there is a serious message in here.
If that helps in terms of New Zealand getting a reputation for being a tolerant, progressive society then I think that's good for New Zealand."
Ellen has around three million viewers per episode.
Mr Key said that if Mr Williamson's airfare was paid for, the minister would have to list it on his pecuniary interests. If he was paid to appear on the show, he would have to donate the money to charity - as Mr Key did when he appeared on the The Late Show with David Letterman in 2009.
Mr Williamson will decide tomorrow whether he will travel to the United States.
His political record has come under closer scrutiny since he stepped into the spotlight.
Asked whether his colleague deserved his status as a defender of gay rights, Mr Key said Mr Williamson had been consistently liberal on conscience issues.
"I don't think you can call it a one-off thing. I don't think in Maurice's wildest dreams he would have thought one and a half, two million people would have been watching Youtube on that particular speech."
Mr Williamson voted against the Civil Union Bill at all three readings in 2004.
A spokesman for Mr Williamson said that the MP felt civil unions did not go far enough and full recognition in the form of an amendment to marriage laws was a better option.
Mr Key said that National was not concerned that its MPs' high profile in the gay marriage debate would harm the party's chances of forming potential coalitions with parties who opposed the law change, such Colin Craig's Conservative Party.
"We're not going to change our position on conscience issues. The caucus fiercely preserves its right for conscience issues, when it comes to abortion, gay rights, alcohol ... so in the end we'll be upfront and tell Mr Craig and anybody else that's our position."