The Federal Opposition says the Government's plans to roll out a national broadband network are looking increasingly like a pipedream.

The tender for the Government's $4.7 billion fibre-to-the-node network closes later this month.

Opposition broadband and communications spokesman Nick Minchin says bidders are frustrated about the lack of detail from the Government.

The project is already months behind schedule and Senator Minchin says that is just one of a litany of problems.

"They've given no indication of legislative and regulatory arrangements that would be for such a bid," he said.

"They're giving no indication whether the $4.7 billion they're talking about of taxpayers' money is going to be a subsidy, or is it going to be a loan, or are they going to buy shares in the business?

"Telstra have said they won't bid unless the Government gives an indication on the issue of structural separation."

Senator Minchin says without Telstra's cooperation, the project will be a disaster.

"Telstra must be part of the scheme because what's being proposed by Labor is an upgrade of the existing network," he said.

"So Telstra's cooperation is essential, one way or the other. And if they don't bid at all, it's hard to see how you can have a realistic bidding process."

The Opposition says the Government needs to rule out structural reform of Telstra to encourage the telco to be a part of the project.