Former prime minister Kevin Rudd says Australia’s national broadband network “train wreck” makes his “blood boil”.

In an interview with TODAY Extra co-hosts David Campbell and Sonia Kruger this morning, Mr Rudd said the current Liberal government’s slow and expensive roll out of the network was “useless”.

NBN is expected to be fully rolled out by 2020.

Kevin Rudd tells TODAY Extra co-hosts the current NBN roll out is “useless”. (9NEWS)

“When we (Labor) introduced the national broadband network, we said we were going to have fibre-optic cable to everybody’s home, business, local schools, hospitals and factories and the reason for that was, not just to watch movies, the reason was it would be a means by which you could grow whole new online businesses and industries which is happening elsewhere in the world,” Mr Rudd said.

“What happen then is they changed the model completely from fibrotic to the home to fibre-optic cable to the node, putting it back onto the punter to then pay for that last link.

“As a result of that, why do you think people are not frankly taking to it because it’s practically useless?

“It makes my blood boil because these guys did a 180-degree change. (They) produced an entirely new NBN while keeping the name and (they) radically change it on whether the cables going to go to your home or somewhere else in the suburb.

“My deep source of anger is that they did so largely in partnership with News Limited because the company has a big interest because they wanted to protect their Fox News cable monopoly.”

Senator Mitch Fifield was grilled by Karl Stefanovic this morning. (9NEWS)

Earlier this morning TODAY co-host Karl Stefanovic grilled Communications Minister Mitch Fifield over the government’s roll out of the network .

"We've turned it around, we’ve got in on track," the senator said.

"NBN is now available to half the nation and it’ll be 75 percent by the middle of next year. It will be all done and dusted by 2020.

The project has cost Australian taxpayers billions of dollars.