Telstra has asked the Australian Competition and Consumer Commission for permission to raise the wholesale price of its copper lines by 7.2 per cent – a move expected to affect about 4 million lines.

If passed on by the telecommunications companies that depend on these lines, the move will lead to more expensive phone and internet services around the country.

Regulatory experts said the issue hangs on two key points. The first is who should bear the cost of building and maintaining the copper network – Telstra or its customers.

The second is whether or not payments from Telstra's $11.2 billion deal with the government and NBN Co to help build the national broadband network should be taken into account.

Telstra argues the NBN's rise will accelerate the migration of customers off its copper network, which means those who remain must pay more for its maintenance.

But Monash University professor and former ACCC commissioner Joe Dimasi said Telstra's argument was flawed.

"Telstra's argument seems to be that because demand for its network is going down then prices should go up," he said. "Telstra should be given a reasonable return by the regulator for its investment ... but it can't be insulated from the rest of the market.

"If we are seeing growth in mobile networks, to then put prices up to compensate for losses on the fixed network is something the ACCC should look at very closely."

He also said it was important for the regulator to look at the bigger economic picture of how price rises could affect the overall market.

"It's important that the decisions they end up with are consistent with good economic practice and give the right incentives for all businesses to invest but also for services to be priced efficiently for everyone," he said.

M2 Group, which owns internet service providers Dodo and iPrimus, would be one of the most heavily affected telcos by the price rise because it is a major reseller of Telstra's broadband products.

It chief executive, Geoff Horth, said he was confident the ACCC would reject Telstra's request and keep prices flat.

"Invariably the price rises would just get passed onto consumers and I don't see how that is in anyone's interests," he said. "The market seems to be operating quite effectively now with robust competition and good growth.

"I don't see any reason to change any of the regulated prices."

He also said the $11.2 billion deal with NBN Co paid Telstra more than enough to compensate for the decline in users and had to be taken into account.

A spokeswoman for Telstra restated the fact that it had not been granted a wholesale price rise since 2011 and that its proposal was for a single increase over the next four years.