He said every forecast made by NBN Co before the 2013 election, and for which there was now data, proved NBN Co's estimates were right. For example, in 2013 NBN Co estimated the average revenue per user per month would be $39 by 2015. The Coalition forecast it would only be $29. In fact, average revenue per user was now at $43. Former NBN boss Mike Quigley is writing a book with Labor MP Jim Chalmers. Credit:Alex Ellinghausen Mr Quigley, a former executive at telecommunications giant Alcatel-Lucent, resigned from the NBN just before the Coalition's election in 2013 and has kept a low profile since. In the speech, Mr Quigley rubbished the copper-based fibre-to-the-node technology, a centrepiece of the Coalition's rollout, and said fibre-to-the-premises (FTTP) "is the only safe long-term bet for Australia's fixed broadband network". "To spend billions of dollars to build a major piece of national infrastructure that just about meets demand today, but doesn't allow for any significant growth in that demand over the next 10 or 20 years, without large upgrade costs, is incredibly short-sighted," he said.

"It is such a pity that so much time and effort has been spent on trying to discredit and destroy the original FTTP-based NBN. "And equally a pity that the Coalition has put their faith in what has turned out to be a short-sighted, expensive and backward-looking MTM [mixed technology model] based on copper. "The nation is going to be bearing the consequences of those decisions for years to come in higher costs and poorer performance in an area that is critical to its long-term future. "Betting tens of billions of taxpayers dollars at this time on copper access technologies, as the Coalition has done, is a huge miscalculation." Mr Quigley said telcos around the world, including companies that have previously been strong proponents of fibre-to-the-node (FTTN), are moving away from the technology.

"Just when the FTTN equipment will need to be upgraded is an unknown but given what is happening overseas, it is unlikely to be very long," he said. As for Labor's election pledge to stop rolling out FTTN and instead deploy full fibre to 40 per cent of premises, Mr Quigley said it was a pragmatic change that would not produce big blowouts in cost or timing. "It will result, however, in a network that is a step closer to the desired end-state," he said. "While it is impossible to turn back the clock on the [multi-technology mix] it is still possible to make changes to the current direction, without introducing another major disruption - changes that will get us closer to building the right network for the long term." Communications Minister Mitch Fifield attacked Mr Quigley's credibility given the rollout delays, missed targets and other problems experienced during his tenure.

"Under Mr Quigley and Senator Conroy the NBN was a failed project," he said. "The Conroy-Quigley team fell one million premises short of their 2013 target. So badly managed was the project that contractors had downed tools in four states. "We've now got the NBN available to 2.6 million premises or a quarter of the nation. It will be half the nation this time next year and the project completed by 2020." In the speech Mr Quigley admitted to some "teething problems" in the NBN's early years under his leadership. "Yes, there were some start-up challenges to overcome but these were being progressively tackled and solved," he said.