In a statement, Labor Shadow Communications Minister Michelle Rowland pointed to an answer offered during Senate Estimates, which asked the NBN Co how many metres of new copper it had purchased uptil 12 June.
NBN Co's answer was that 16,600 km of cable had been purchased, "primarily to make the connection between node cabinets and pillars. Since that time, an additional 4478 km has been purchased".
Rowland said this meant a total of 21,078 kms of new copper had been bought for what was initially meant to be a predominantly fibre network.
"Unfortunately, while (Australian Prime Minister Malcolm) Turnbull enjoys top speeds of 100 Mbps at his Point Piper residence, 3 in 4 Australians on fibre to the node cannot achieve those speeds."
When construction of the NBN was begun, the Labor Party was in office and it envisaged fibre being rolled out to the premises for 93% of the populace, with the remaining 7% to be supplied with connectivity through either wireless or satellite.
The rollout became a political issue when the Coalition Government that took power in 2013 decided to change the technology of the network to what it called a multi-technology mix.
The MTM includes fibre-to-the-node, HFC cable, satellite, and wireless, apart from fibre-to-the-premises which is being provided only to new dwellings.
As the MTM plan and the connections provided have come under increasing criticism, fibre-to-the-distribution-point, which considerably reduces the copper lead-in to premises — what the network builder NBN Co calls fibre-to-the-curb — has been introduced as well.
"Worse still, leaked documents from 2015 revealed the cost of NBN copper remediation had blown out by $600 million. This was a tenfold increase on what was claimed in the December 2013 NBN Strategic Review," Rowland said.
"On every measure, Turnbull’s $49 billion multi-technology mix has not been faster or cheaper – it costs more and does less.
"Labor again calls on the government to abandon its second-rate copper rollout wherever feasible, and at a minimum take fibre to the kerb."