Labor says the national broadband network rolled out by the federal government has been a "monumental stuff-up" and voters have a right to be annoyed.
Shadow assistant minister Terri Butler made the comments on Wednesday in response to news that three in four Australians connected to the NBN via a neighbourhood node wouldn't be able to access its top speeds.
In response to a Senate committee, NBN Co estimated only 24 per cent of premises connected by fibre-to-the-node technology at the end of the scheme's rollout would be able to access 100 Mbps or more.
It showed only those connected via fibre to their premises, building or through existing pay TV cables would be able to access the high speeds.
Ms Butler said people were frustrated with the unreliability of the technology the government had delivered.
"There are so many problems with this NBN, it's been an absolutely monumental stuff-up by (Prime Minister) Malcolm Turnbull from start to finish," she said in Brisbane on Wednesday.
"I think people are right to be annoyed."
Ms Butler said the government's decision to replace fibre-to-the-home with a multi-technology mix meant people were now getting a "second-rate NBN".
"They're getting an NBN that drops out, they're getting an NBN that isn't giving them the speeds that they're expecting," she said.
An NBN Co spokeswoman said fibre-to-the-node provided "average wholesale download speeds of about 70Mbps", which was about 10 times faster than average ADSL in Australia.
"NBN's current plan is to get the network completed by 2020 with all premises able to access at least 25Mbps and 90 per cent of the fixed-broadband footprint able to access speeds of 50Mbps," she said in a statement to AAP.
"Once we have completed the network build and have eight million premises connected to the network we will be generating annual revenues of around $5 billion."
The spokeswoman said the income stream would be used to fund network upgrades to enable "higher speed services" to be rolled out without additional government funding.
"Moving to the multi-technology model has enabled us to vastly accelerate the deployment and adoption of the NBN network and we are in a good position to deliver future upgrades when required," she said.
