Scott Morrison's government is being urged not to use new religious laws to facilitate more discrimination against Australians of various sexualities.
New religious freedom laws could end up entrenching more discrimination than they alleviate, according to the Greens.
Their concerns come as lesbian, gay, bisexual, transgender and intersex Australians have been urged to make their feelings on the issue known to Attorney-General Christian Porter.
Prime Minister Scott Morrison intends to make it unlawful to discriminate against people based on their religious beliefs, and Labor is backing his push, but the Greens are worried the laws could make it easier to discriminate against LGBTI people.
Greens senator Janet Rice said the party supports the rights of people of faith.
"But that does not mean that they should have a licence to discriminate against LGBTI people," she told reporters in Canberra on Thursday.
"We are deeply concerned that the Morrison government's proposed religious discrimination bill will be just that - it will be a Trojan horse to extend and entrench more discrimination in our laws, rather than just reducing it."
LGBTI rights group just.equal holds similar concerns, with spokesperson Rodney Croome urging sexuality-diverse groups to chip in to the government's consultations on the changes.
"It is vital the government hears diverse LGBTI community voices, especially those concerned about the potential erosion of LGBTI legal rights in the name of religious freedom," he said.
Mr Morrison is proposing to amend existing marriage, charities and anti-discrimination legislation.
A religious discrimination commissioner would also be appointed at the Australian Human Rights Commission.
The new Religious Discrimination Act could be brought before parliament as early as July 22.
Labor senator Kristina Keneally said the opposition would embrace that consultation.
"We are waiting to have those conversations. We do stand ready, though, to work with the government on this," she told ABC radio.
Coalition backbenchers will be given the chance to shape the laws through workshops with the attorney-general.