Australia's $8 billion National Broadband Network (NBN) has been set back for at least another 12 weeks, after the government bent under pressure to extend the tender October deadline.

Communications Minister Stephen Conroy has long been criticised for not supplying enough information for bidders to construct sufficient plans to build the network.

Members from Telstra and the Optus-led Terria consortium, formally the G9, now have slammed the Fibre-to-the-Node (FttN) tender documents and labeled them "watery" and insufficient.

Specifically industry argues that the documents do not provide data on Australia's telecommunications infrastructure, or the pricing and regulatory environment in which the winning bidder will have to operate the network.

Conroy successfully passed a bill to safeguard sensitive network information held by infrastructure owners including Telstra and PIPE networks, after the companies refused in Februrary to supply the data to government.

The opposition failed to squeeze amendments into the bill to force the government to reveal more information about the NBN environment, including architecture, and wholesale access models.

Contenders will have 12 weeks to place a bid from the time "all material is made available" to the tender documents.

Ovum director David Kennedy said he is not surprised of the deadline extension. "The government has been pushing too hard to meet a political timetable," Kennedy said.

"The Government should aim for the right result, not a quick result.

"A few extra weeks to ensure that the process is genuinely competitive are well worth any additional delay."

Shadow communications minister Bruce Billson has lodged a complaint with the Auditor General regarding the tender process.