NBN Co chief executive Bill Morrow has effectively told a Senates Estimates committee that the four million Australians who receive a fibre to the node connection to the NBN will have to pay if they want to upgrade it in the future.

Morrow told Senator Deborah O’Neill on Tuesday that people would have to pay more for superior technology to receive faster broadband speeds than can be delivered via FttN.

Earlier, Communications Minister Mitch Fifield told the committee that the government's NBN strategy was based on the best advice available at the time.

Internet Australia chief executive Laurie Patton said today that these statements underlined the need for the government to give up on FttN and adopt fibre to the distribution point instead.

On Tuesday, the NBN Cothat 700,000 premises would be getting FttDP technology, which it chooses to call fibre to the curb.

Patton, who has been a tireless advocate for abandoning FttN, said: "They’ve already announced they’ll use FttDP in lieu of the Optus HFC (Pay TV) cables that have been found to be unusable.

"So why continue to roll out inferior technology that they know will need to be replaced? If FTTN isn’t considered good enough for Optus customers how can they expect anyone else to settle for an inferior product?”

IA said it was disturbed by some of the messaging coming from NBN Co, adding that last week, a Brisbane-based NBN Co spokesperson had tweeted that "we have an upgrade path to take FttN to 1Gbps downloads".

This prompted the organisation to seek clarifications from NBN Co, which, it says, have not been provided despite several requests.

“Morrow’s evidence to the Senate last night directly contradicts his own PR people. If they did have an upgrade path why would he tell the Senate that people wanting faster speeds will have to pay to get different technology capable of delivering what they want?" Patton asked.

He said IA was calling on the government and Opposition to jointly support a bipartisan NBN policy based on FttDP.

“Our internationally respected technical experts assure me there is no such thing as an upgrade path for FttN and it will need to be replaced within 10 to 15 years, if not sooner," Patton said.