Proposed changes to copyright law would mirror Labor's dumped internet filter and would not curb online piracy, the free market think tank the Institute of Public Affairs has said.

The IPA has slammed ideas raised in the government's discussion paper and warned there is a "real risk" Attorney General George Brandis will push ahead with the proposals "in defiance of Liberal values".

The government is calling for debate about an idea to introduce a new special injunction that would force Australian internet service providers to block sites which enable illegal downloads of content such as films or television shows.

It is one of several proposals included in the Online Copyright Infringement discussion paper that Attorney-General George Brandis and Communications Minister Malcolm Turnbull released at the end of July.

In its submission to the government, the IPA has slammed the proposals and described them as a threat to free speech and predicted the measures will be ineffective.

"The policy resembles the previous Labor government's internet filter, and, like the internet filter, represents a threat to freedom of speech and digital liberty," the IPA argued.

"The government lampooned these ideas when Labor proposed them," the IPA's Simon Breheny told Fairfax Media.

"Alarmingly, this is a Liberal government that prior to the election made promises on freedom of speech. We expect a Liberal government to adhere to liberal values and this policy does anything but," he said.

Furthermore, the IPA argues that such injunctions would be easily bypassed by users buying a Virtual Private Network, or as they are commonly known, VPN.

"VPNs are not tools of a savvy, narrow elite," the submission said.

The IPA's 18 page submission also argues the proposals would see the costs of copyright protection unfairly shifted onto the internet service providers. The IPA believes a better way to deal with online piracy in Australia would be to introduce a "fair use exception".

Mr Breheny said he was "concerned" and "alarmed" that the government was not placing more emphasis on the importance of innovation and technological advances, such as content streaming platforms, to resolve piracy issues over ineffective regulations. He said ultimately rights holders needed to take responsibility by ensuring their content was accessible and affordable.

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