Anglican Bishop Stuart Robinson fears changes to the ACT Discrimination Act could lead to religious disputes ending up in court and increase tension between faiths.
The head of the Canberra and Goulburn Archdiocese has also criticised the ACT government for not consulting religious leaders about the proposed changes, which will make religious vilification in the territory illegal.
But Attorney-General Simon Corbell, who will introduce the legislation next week, says the proposed amendments are ''not controversial'' and have been consistently recommended by the ACT Human Rights Commission.
The proposed change would add the word ''religion'' to the list of serious vilification offences in the Discrimination Act, which already prohibits vilification on the grounds of race, sexuality, gender or HIV/AIDS status.
Mr Corbell's bill follows the recent campaign against the Gungahlin mosque development by the ''Concerned Citizens of Canberra''.
The ACT Greens said they would support the proposal ''in principle'', but Mr Corbell could be forced to move the bill as a matter of urgency if it is to be debated next week.
Bishop Robinson said he supported improving basic human rights, especially the freedom to choose and practise a religion. But he said open societies also gave citizens the right to disagree on religious beliefs and practices.
''Balancing these two competing rights is difficult and there have been serious problems with religious anti-vilification laws in other jurisdictions, particularly Victoria,'' he said. ''If the proposed new law results in doctrinal disputes ending up in courts then it will actually increase tensions between people of different faiths or none.''
Bishop Robinson said the bill was well-intended but had been done in a ''knee-jerk'' way without consultation.
Monsignor John Woods, administrator of the Catholic Archdiocese of Canberra and Goulburn, said he supported the government's motivations for changing the act, but questioned whether it would work in practice. ''I applaud the intent, however I question whether the material can deliver or would it perhaps create more problems than it solves?''
But Monsignor Woods ''unreservedly condemned'' anti-Islamic material that had been distributed throughout Canberra this year.
Mr Corbell said the amendments would not inhibit freedom of speech or expression about matters of religion.
''This is not a knee-jerk reaction, this proposal is based on the recommendations of the Human Rights Commission which has consistently recommended these changes for a number of years.''
Greens MLA Shane Rattenbury said there were passages in the legislation that provided the ''appropriate balance'' for freedom of speech.
Canberra Islamic Centre president Azra Khan welcomed the bill. ''My feeling is that [the amendment] would be supported widely.''