As Labor and the Greens condemned the move and Twitter erupted, Attorney-General George Brandis praised Mr Wilson as "one of Australia's most prominent public advocates of the rights of the individual".

"He was at the forefront in thwarting recent attempts to erode freedom of speech, freedom of the press and artistic freedom rights and freedoms Australians have always held precious," Senator Brandis said.

He warned that the commission had "become increasingly narrow and selective in its view of human rights" under Labor.

Opposition legal affairs spokesman Mark Dreyfus questioned the appointment.

"By appointing Mr Wilson, Senator Brandis has sent a strong signal about exactly the kind of blatant political agenda he wishes to pursue as Attorney-General," Mr Dreyfus said.

"Earlier this year the IPA made a submission to the Senate Legal and Constitutional Affairs Committee calling for the abolition of the Human Rights Commission. How can Mr Wilson possibly undertake the role of a human rights commissioner when it's obvious he has such contempt for the commission itself?"

Greens spokeswoman Penny Wright said the government "cannot be trusted to look out for all Australians".

"The Attorney-General has already made it clear he thinks some human rights are more important than others, including that free speech ought to trump anti-discrimination laws," Senator Wright said.

Mr Wilson, 33, is a graduate in public policy from Monash University. He has spent seven years with the Institute of Public Affairs think tank, where he has headed up its climate change policy and intellectual property and free trade unit.

He is also a senior fellow at New York's Centre for Medicine in the Public Interest.

Former Australian youth representative to the UN Samah Hadid slammed the appointment as "an absolute farce". Support for the appointment came from Australian Marriage Equality national director Rodney Croome, who praised Mr Wilson as a long-time supporter of same-sex marriage.

Politics and HRC appointments are no strangers. Mr Wilson's fellow commissioners include Hawke government minister Susan Ryan and Tim Soutphommasane, a former ABC presenter, fellow of left-leaning think tank Per Capita and staffer to Bob Carr during his days as NSW premier.

News Limited columnist Andrew Bolt, who in 2011 fell foul of provisions in the Racial Discrimination Act Senator Brandis has pledged to repeal, welcomed Mr Wilson's appointment but contrasted the ABC's reporting of it with its coverage of Dr Soutphommasane's.

"I'm startled," Mr Bolt said. "Tim Soutphommasane was a Labor member from a left-wing think tank and he is welcomed; Tim Wilson was a Liberal member from a conservative think tank and he is attacked.

"If ABC chairman Jim Spigelman wants evidence of ABC bias look at the coverage of Tim Wilson's appointment."

Senator Brandis charged Mr Wilson with the task of protecting "the traditional liberal democratic and common law rights", including, in particular, freedom of expression.

He told The Australian: "I chose Tim Wilson for this role because I saw in him a person who had the philosophical integrity, political smarts and personal toughness to take this cause to the heart of the action."