The Federal Government was pressing ahead with talks with the three ISPs that volunteered to participate in an internet filter.
Department of Broadband, Communications and the Digital Economy deputy secretary Abul Rizvi told a Senate Estimates committee that it was talking to Telstra, Optus and iPrimus, which "indicated they will implement voluntary filters and talking to the industry body association for ISPs on what's needed for them to proceed".
The Government was also working to "provide assistance on the possible design" of a review of refused classification guidelines the Government said must be completed before it considered introducing mandatory ISP-level filtering.
The public would also be asked to make submissions to the review, said Communications Minister Senator Stephen Conroy.
The Standing Committee of Attorneys-General would handle the review overseen by the Minister for Home Affairs and Justice Brendan O'Connor.
The committee was due to meet next month although it was unclear whether the RC review was on its agenda, The Australian reported.
Senator Conroy said he was "reasonably confident" that the review would not be put on hold or delayed by objections from the states.
He said the Government "sounded out" the states before announcing the RC review in July but denied it was proceeding only after assurances of a favourable outcome
"I wouldn't want to predict what the outcome would be," Senator Conroy said.
He denied suggestions that mandatory ISP-level filtering was to "sit on the backburner for quite some time".