Prime Minister Malcolm Turnbull has slapped down conservative Coalition MPs clamouring for the right to discriminate against gay people, arguing such moves would be neither welcome nor successful.

He was responding to demands from some Liberals, led by Victorian senator James Paterson, that business owners should be able to refuse service for gay weddings based on religious or "conscientious" beliefs.

Prime Minister Malcolm Turnbull addresses the media from the ASEAN summit in Manila, on Tuesday. Credit:Alex Ellinghausen

Senator Paterson on Monday published a bill that would legalise same-sex marriage but roll back discrimination laws to ensure nobody is forced to help facilitate a same-sex ceremony or reception.

It involved overriding existing discrimination laws and creating special dispensation for the "relevant belief" that homosexual relationships are unholy or immoral.