Opposition senators have called on the federal government to release the $25 million study on the $43 billion National Broadband Network (NBN), which has been touted by the government as Australia's largest infrastructure undertaking to date.

In a report by ABC, Greens Senator Scott Ludlam urged the government to shed more light on the project as he lamented that no specifics have been made available ever since Prime Minister Kevin Rudd enjoined investors last year to get involved on the project.

Senator Ludlam, one of seven legislators that could determine the fate of NBN, said that the only information they can consider so far are the opinions offered by Communications Minister Stephen Conroy, as he stressed the importance of knowing "what kind of business it is going to be, what it's going to cost, what wholesale prices will be."

He added that a careful appraisal of the NBN study should influence the Greens' vote on the project, underscoring that "we certainly won't be voting on it until we've had a proper look at the economics of the proposal, because it's a huge amount of taxpayers' money."

Opposition spokesman Tony Smith conceded that a better broadband would be beneficial but scored the Labour government's expensive approach on the project and suggested that the private sector will be much qualified to handle the broadband network.

Senators Steve Fielding and Nick Xenophon are both looking at the NBN study to provide them the necessary information in giving their approval on the project, with Senator Fielding voicing his concern on the project's cost stressing that, "It's a heavy price tag and I have concerns at that price level. That's why the implementation study is important."

Private sectors are also airing their concerns with Ovum research director David Kennedy projecting that NBN's success will weigh heavily on cooperation between the government and Telstra, as he stressed that "for a network this expensive to be a commercial proposition it would have to be at a minimum essentially a monopoly."

Mr Kennedy said that NBN and Telstra must close a deal which should transfer traffic from Telstra's old network to NBN, warning though that if such deal will not be realised and the two companies eventually become competitors "then it's difficult to see penetration in the short-to-medium term getting much above 30 or 50 percent."