The Morrison government has quietly mothballed an inquiry which would have paved the way for long-promised laws to protect gay students and teachers from being expelled or sacked from religious schools.

The Australian Law Reform Commission has not yet started work on the inquiry, which was first referred to it nearly a year ago. President Sarah Derrington requested the deadline be extended until 12 months after the government's Religious Discrimination Bill passes Parliament - which is not guaranteed - making it highly unlikely any recommendations will be legislated before the next federal election.

Attorney-General Christian Porter made the change on March 2 but it was not announced by the government. The amendment appeared on the relevant webpage on the ALRC website last week.

Prime Minister Scott Morrison and Attorney-General Christian Porter. Credit:Alex Ellinghausen

Mr Porter told The Sun-Herald and The Sunday Age the delay "makes good sense as it will enable the commission to take into account the extraordinarily far-reaching public consultation process we undertook in developing the Religious Discrimination Bill".