CHRISTIAN Democrats Leader Fred Nile says he supports a national poll on gay marriage because the majority of Australians will reject the move.

"The information that I get when I'm travelling around is that there's no support for same sex marriage.

"In fact, quite a few people are very angry about it, especially minority groups," he told AAP.

As examples, the conservative NSW politician pointed to Muslims, and Korean and Chinese Christians.

"A lot of people make up these monitory groups and they have strong conservative views on this issue, as does Asia. It's against their religion and culture."

Rev Nile has emerged as a backer for the move after independent federal MP Tony Windsor swung his support behind a plebiscite being held alongside the September election.

Rev Nile said it would take pressure off politicians in Canberra, as well as speculation about conscience votes, and "I believe the majority of Australians will say no".

But he said the right question would need to be asked of voters.

"It can't be 'are you in favour of marriage equality' because a lot of people think that means between a husband and a wife.

"It needs to be 'are you in favour of two homosexual men being able to get legally married'."

Originally published as Fred Nile backs gay marriage poll