The Federal Opposition and the Greens have criticised the government for exempting the National Broadband Network Company (NBN Co) from freedom of information (FOI) laws.
NBN Co, tasked with rolling out the national fibre network, will not be subject to the FOI Act because it is an incorporated company.
Prime Minister Julia Gillard has stood by the exemption.
"[The system] is one where something like NBN Co is not covered by [FOI laws] and it is ordinary business," Gillard told reporters in Melbourne today.
NBN Co has previously refuted industry accusations that the company keeps its cards close to its chest and has argued that it is "highly transparent".
However, Shadow Communications Minister Malcolm Turnbull said the government is avoiding scrutiny and that the Opposition would challenge NBN Co's exemption in parliament.
"The government, when it came into office, said every major infrastructure project would be subject to a rigorous cost-benefit analysis, [that it would] open up freedom of information laws and it would provide greater scrutiny.
"And yet with this, the greatest infrastructure project in our history, there is no analysis being allowed. There is no Productivity and Inquiry."
The exemption has also angered the Greens, which will push for NBN Co to be subject to the FOI Act when parliament resumes next month.
The party was successful in pushing through a number of amendments to Labor's draft laws, aimed at increasing transparency, in the Senate in late November when the structural separation of Telstra was passed.
Greens Party Communication Spokesperson Scott Ludlam said it was unacceptable for a public enterprise investing about $27.5 billion of taxpayer's money to be exempt from FOI laws, which allow access to government-held information.
"I haven't ruled out government support yet, so the first step from our point of view is to make sure it can be done, which we're pretty confident we can do it with a private senators' Bill and then we'll have the debate," he said.
The Greens will need the support of the government or the Coalition to pass the draft law amendments.
The minor party refused to support the Coalition in its calls for the NBN project to be subject to a full cost-benefit analysis and will rely on the Coalition's support to pass its own amendments to put NBN Co under closer scrutiny.
Ludlam said an incorporated body could be covered by the FOI Act if it was established by a minister or an incorporated company over which the Federal Government was in a position to exercise control. He said NBN Co met both of those criteria.
Government-run corporations, including Australia Post and the ABC, were subject to FOI laws but their commercial dealings could still be protected under commercial in confidence considerations.
"We think those same tests should be applied to the NBN. I don't understand why the government has left them off," Ludlam said.