NBN Co chief executive Bill Morrow's claim that any upgrades to Australia's national broadband network will be funded by the company itself have been called into question by Internet Australia executive director Laurie Patton.

In a speech to the American Chamber of Commerce on Monday, Morrow was quoted as saying: "We've built the network so it's readily scalable. And, as the need grows, we will put those technologies in place. Importantly, we'll fund these upgrades ourselves. We won't need to call on taxpayers."

Patton pointed out that in comments to Senate Estimates, Morrow had said that people who wanted upgrades would have to bear the cost themselves.

"So which answer is the correct one? I suspect most people have a pretty good idea," Patton said.

He called on NBN Co to abandon what he described as a "misleading PR campaign", arguing that the people of Australia were not being deceived by the spin.

Patton (right) reiterated IA's call for the government and Opposition to say openly that NBN's reliance on Telstra's "ageing copper wires" meant the network was incapable of meeting future demand.

"It's time all our political parties agreed we need a future-proofed NBN and it's time NBN Co stopped trying to convince people that that's what they're building," he said.

With regard to Morrow's claim that NBN Co could fund future upgrades, Patton said the copper-based FttN network, which was being supplied to 40-50% of households, was not at all scalable.

"Our globally recognised technical experts estimate it will have to be ripped out and replaced, at great cost, within 10 to 15 years of completion or even sooner," he said.

"NBN Co recently borrowed $19 billion from the government. They'll struggle to pay that back any time soon, much less have the money for the upgrades."

In his speech on Monday, Morrow claimed that the lack of high-speed Internet uptake had nothing to do with NBN's wholesale pricing regime.

However, Patton pointed out, complaints from retail service providers had resulted in Communications Minister Mitch Fifield ordering a pricing review.

"There's no doubt the wholesale cost of the higher speed tiers is discouraging RSPs from offering them to their customers. I've even had people tell me their RSP actually tried to persuade them to take the minimum speed package," he said.

Patton said Morrow had also appeared on radio station 3AW on Monday where host Neil Mitchell had noted that every time he mentioned the NBN he received angry calls from listeners. Mitchell also took a number of such calls that promptly proved the point, he added.