Opposition communications spokesman Malcolm Turnbull has repeated calls for a cost-benefit analysis of the Federal Government's National Broadband Network plan, but couldn't guarantee bipartisan support for the NBN project should such an analysis endorse it.

Turnbull on Sunday said that a "big tick" from a Productivity Commission-led analysis of the National Broadband Network would be "incredibly persuasive", but he again stopped short of saying he would support the broadband project in that eventuality.
Turnbull is due to introduce to parliament today a private members bill seeking to force a cost-benefit analysis on the national broadband network.
Yesterday, Turnbull again faced the question of what he would do if the cost-benefit analysis he consistently called for came up in favour of the Government's NBN project.
He told iTnews last month that he wouldn't commit to support the $43 billion project in the "unlikely" event that such an analysis concluded fibre-to-the-home should proceed.
And a month later, his position appeared not to have changed, despite at least one report suggesting Turnbull's comments heralded the coming of bipartisan support for the NBN.
"I would not, as a matter of principle, give a blank cheque to anyone, even the Productivity Commission, but if the Productivity Commission were to report on the NBN as they should, and if they were to give it a big tick from a cost-benefit point of view, it would be incredibly persuasive," Turnbull told Channel Ten's Meet the Press yesterday.
"I think it would obviously change a lot of people's perceptions.
"It would have a huge impact but nobody in their right mind gives a blank cheque to anyone, even someone as a well resourced as Gary Banks and the Productivity Commission."
Turnbull did not specify whether he or the Coalition would be persuaded by a positive outcome of a cost-benefit analysis.
Turnbull claimed yesterday that relatively static growth in fixed line broadband connections compared to mobile broadband was proof that investing in a next-generation fixed network was flawed.
"The government is... backing one technology where every indication from the market is that it is moving in another direction," he said.
Turnbull also said that the shadow cabinet and Liberal Party would examine the text of the re-introduced Telstra split bill this week.
Does the NBN need a cost-benefit analysis? Read telco expert David Havyatt's case for and against here and have your say in our poll on the iTnews home page.