Greens agree to deal on NBN

The federal government has secured the support of the Australian Greens for its national broadband network after agreeing to allow a parliamentary vote on any future privatisation.

But Labor is no closer to winning over independent senator Nick Xenophon, whose vote could stymie the $43 billion project.

The government has agreed to include a clause in its NBN legislation that requires parliament to approve any plan for the network's privatisation.

"That was the last issue that was a sticking point for us," Greens communications spokesman Scott Ludlam told ABC Radio on Monday.

The clause would prevent the NBN from being automatically privatised, he said.

"It will need to be subjected to a full and comprehensive public interest test done partly by the Productivity Commission and partly through a joint parliamentary committee."

If a government insisted on going ahead with the network's privatisation it would need to be submitted to parliament for approval.

With the Greens on board, the government needs to secure the votes of Nick Xenophon and Steve Fielding.

Either one, voting with the opposition, could sink NBN-related legislation starting with a bill for the structural separation of Telstra that will be debated in the Senate this week.

Communications Minister Stephen Conroy says both senators have given positive indications of support for the NBN.

But the NBN business plan, which the government refuses to release until December when parliament is in recess for the long summer break, remains a sticking point for Senator Xenophon.

The senator has rejected the offer of a confidential briefing on the plan, because he would have had to sign a non-disclosure document.

"Some of the terms were just not on," he told ABC Radio, adding that the initial non-disclosure period of seven years was less than the prison time for killing someone.

"Then it was changed to three years and last night it went down to two weeks."