"Government has changed and policy has changed so what is the one constant over the next decade? That the government will change and the policy will change," he said. "As long as we keep building the damn network, as long as the fibre keeps getting closer to consumers and going in that direction we will reach that nirvana at some point."

But Mr Hackett was more supportive of NBN using the Hybrid Fibre Coaxial (HFC) connections that are currently used by millions of Australians to get Foxtel services and cable broadband from Telstra and Singtel-Optus.

Communications Minister Malcolm Turnbull said Mr Hackett was correct but that financial circumstances prevented the rollout of more fibre optic cabling.

"Simon is right in the sense that the goal is always to push fibre deeper into the network to its most economic point," he said. "If it weren't for time or money, you would deploy fibre-to-the-home everywhere and Government policy in the future will change, regardless of who's in power, as deployment costs are lowered and the capacity of available technologies is bolstered.

"Unfortunately it remains the case that on current costs, the NBN Co's fibre to the premises rollout is the most expensive in the world ... and the economic benefits of deploying a multi-technology mix exceed a full fibre rollout by $16 billion."

Mr Turnbull has also previously said that his technology is designed as a stepping stone on the path to connecting more premises directly to fibre – a move critics say will cost more time and money.

Under the Coalition's current plan, about 29 per cent of premises will get fibre-to-the-node, which runs fibre to a streetside cabinet before switching over to existing copper phone line connections that run into the homes.

Shadow communications minister Jason Clare used Mr Hackett's comments to attack the Coalition's policy.

"Malcolm Turnbull sacked the NBN Co board because they didn't agree with him," he said. "A year and half later, Turnbull's hand-picked replacement has come to the same conclusion - his second-rate copper NBN is a dud."