Labor Senator Kate Lundy is pushing for an ‘opt-out’ feature, while four Liberal MPs are fighting from within the Coalition.

“I do not believe a mandatory filter will achieve the policy goals stated and I agree that mandatory filtering creates an issue around free expression and business confidence. However, I know there are many Australians, particularly those with children who would choose a filter option given the choice,” said Senator Lundy.

“I believe that the best path forward is one of mandatory choice where as part of their normal interaction with an ISP all subscribers are provided information about filtering so they can make an informed choice (to filter or to not filter).

“I think mandating the provision of an Open Internet service in legislation for all ISPs also protects the civil libertarian principles of freedom of information and speech whilst not diminishing the ability of the authorities to tackle illegal content such as child pornography where is found.”

However, Stephen Conroy says the purpose of the filter is to keep out obscene and harmful materials, and believes that such materials should be illegal.

“RC-rated content includes child sexual abuse material; bestiality; sexual violence including rape; detailed instruction in crime, including suicide-related material; violence or drug use; and/or material that advocates the doing of a terrorist act,” a spokeswoman for Senator Conroy told The Australian.

“RC-rated content is not available in newsagencies, it is not on library shelves, you cannot watch it on a DVD or at the cinema and it is not shown on television. The government believes this content has no place in a civilised society.”

The proposed filtering legislation is scheduled for parliamentary debate next month.