The National Broadband Network (NBN) infrastructure already in place would not be wasted by a Liberal government should it be voted into power come the next election.

This according to opposition communication and broadband spokesman Malcolm Turnbull as he said on Tuesday that ditching the existing copper wire network currently utilised by Australia in favour of the fibre optic network would be a wasteful effort from the Labor-led government.

Speaking before the AB+F Corporate and Business Banking Forum held in Sydney, Mr Turnbull balked at the idea of junking a perfectly working communication infrastructure in rolling out the federal broadband project as he assured his audience that "you can be sure that we won't start ripping things up."

He scored, at the same time, the federal government's faux pas of not undertaking a thorough cost-benefit analysis prior to the actual expenditure of the $43 billion allocated for implementing the NBN roll out.

Mr Turnbull said that it was "simply reckless and irresponsible" for the government of Prime Minister Julia Gillard to succumb to such act of omission as he stressed that "the Gillard government must urgently undertake a thorough cost benefit analysis of the NBN."

The opposition spokesman pointed out that such stubborn failure of overlooking an important element of a costly and high-profile government initiative "could only lead us to conclude that it does not want to know what it fears it will reveal."

Mr Turnbull further argued that the ballooning capitalisation of the NBN project could eventually result to expensive costs for households availing of the broadband services and worst, substantial bleeding of taxpayers' money just because of a crucial government blunder.

In the end, Mr Turnbull said that the government would be forced to charge higher prices for the NBN services or end up absorbing losses as it resort to political accommodations by subsidising costs and falling short of targeted revenues from its investment that runs to billions of dollars.