Federal Labor says the government has broken a pre-election promise to deliver the national broadband network to all Australians by the end of 2016.

But the government argues the opposition is distorting the facts.

Opposition communications spokesman Jason Clare says the NBN's large-scale rollout has yet to start despite the communications minister's website stating that it would "commence in mid-2014".

The budget papers showed $500 million of earmarked spending on the NBN had been pushed into future years.

"Malcolm Turnbull is not only leaving Australians with a second-rate, short-sighted NBN that relies on 20th century copper instead of 21st century fibre, the rollout of it is slower than he promised," Mr Clare said.

Mr Turnbull said that at the time of the 2013 election only two per cent of Australian premises could access the NBN.

Since September 2013 the number of Australians who could connect to the NBN had increased four-fold, to 918,000 in the fixed line and fixed wireless footprint.

NBN Co was on track to hit its target of 1.1 million premises passed by June 30.

The number of NBN-serviced premises had risen from 90,500 in September 2013 to 421,000 last week.

"Mr Clare's claims of a slower than planned rollout under the coalition revealed by budget forecasts of equity investment are pure fiction," Mr Turnbull said.