Christian advocacy organisation FamilyVoice Australia is calling on the Prime Minister to keep faith with the voters by warning backbenchers that no parliamentary legislation will be presented by the Executive Council for Royal Assent without permission of the Australian people.

"It is not sufficient for the Prime Minister to defend the role of backbenchers," said FamilyVoice National Director Ashley Saunders.

"He must inform them that the Executive Council will not present same-sex legislation to the Governor-General for his assent. To do so would be to break faith with the Australian people who were promised a plebiscite," he said.