Former Communications Minister Stephen Conroy has conceded the former government "clearly underestimated" the challenge required to meet the NBN's "ambitious" construction targets and timeframes.
Speaking publicly for only the second time since giving up the communications portfolio, Conroy told an ACS telecommunications industry function that the former government "underestimated the capacity of the construction industry to respond to the challenge".
"That has led to the majority of the publicity around the alleged blowouts," he said. "... The construction model could be legitimately criticised".
Conroy also conceded that the former government may have over-estimated what was possible for NBN Co to accomplish as it attempted to scale up from being a "startup company".
With the benefit of hindsight, he questioned whether the former government would have "been so aggressive if we'd realised how tough it was for the company".
Adding to NBN Co's challenges were the approaches taken to bring the NBN into multi-dwelling units — home to some 34 percent of Australia's population, according to Conroy — and to greenfields areas, where the rollout had well-documented issues.
However, Conroy believed that the project had still been "well managed" when it was considered in totality. Only one of five major pieces of work — listed as the fibre, wireless and satellite access networks, transit network and IT systems — could be described as "significantly lagging", he said.
"[Considering] the relative scale of calamity that could befall a project of this size, you have to say on balance [that] the NBN Co project has been well managed if you look at the totality, not just how many leads have been put into homes over the last three years," he said.
Conroy, however, said he empathised with voters who were "disappointed with the progress on the fibre rollout".
"But let's be clear - any further delays to the rollout beyond the schedule in the revised plan that has now been submitted to Mr Turnbull will be a consequence of his policies and his changing policy agenda," Conroy noted.
Conroy used much of his address to lament an alleged lack of understanding by the Coalition on the issue of the digital economy.
He said Labor's naming of the communications portfolio as the Department of Broadband, Communications and the Digital Economy (DBCDE) highlighted the importance of a national discussion on the digital economy. The Coalition has since rebranded it as simply the 'Department of Communications'.
Conroy said the Coalition's "fundamental error" was in not understanding the ties between the broadband and digital economy policy agendas.
"[The Coalition] don't understand that we are building the NBN because of the promise of the digital economy," Conroy said. "We're not talking about the digital economy to justify the infrastructure investment."
Conroy also used his address to position Labor's "nation-building agenda" as being broader than that of the Coalition Government.
"A common but inaccurate refrain in public commentary about politics is often that there's not a lot that distinguishes our two main political parties," he said.
"The role of government in nation-building is one of the major dividing lines between the parties. Since the Liberal revolution in the 1980s, the conservatives around the world have shied away from nation-building."