NBN not planned by politics: Quigley

National Broadband Network Company (NBN Co) CEO Mike Quigley has rejected suggestions from the Coalition that the 28 new sites announced yesterday were mostly kept out of Liberal and National electorates.

Yesterday afternoon, Liberal MP Paul Fletcher suggested that only seven of the 28 sites announced were in safe Liberal electorates, with 80 per cent of the total sites in seats held by Federal Labor, Greens, Independent members of parliament and seats that are marginally held by the Coalition.

"Based on initial analysis of the NBN roll-out figures released today, it appears that NBN roll-out decisions are being taken for political reasons," Fletcher said.

In a Senate Estimates hearing yesterday evening, Quigley said that technical factors such as the availability of exchange space and dark fibre from Telstra were most influential in determining the next 28 sites for the NBN fibre roll-out.

"The availability of that infrastructure is dependent on Telstra being able to free up exchange space and free up dark fibre," he told the hearing. "Overwhelmingly in these early stages, the availability of Telstra infrastructure dictates where we can go in the roll-out."

The Telstra shareholder vote in favour of the $11 billion NBN deal yesterday has cleared the way for NBN Co to begin leasing Telstra's infrastructure as part of the deal, and Quigley said the vote passing was good for all involved.

Other factors such as the contracts signed with construction companies, the roll-out into new housing developments, the roll-out of NBN Co's long-term evolution (LTE) fixed wireless service and the decision to extend existing NBN sites all played a major role, Quigley said. He added that the government had directed NBN Co to roll-out to a mix of regional and metropolitan areas.

Quigley also indicated that NBN Co was rolling out the fibre in ringed formations so in the event of the fibre being cut off in one area, data traffic could still be delivered from the other side of the ring.

Although NBN Co had yet to finalise construction contracts in the Northern Territory and South Australia, Quigley said that the sites listed in those areas today would still go ahead as planned. He said that the company plans to announce the signing of the contracts in the next month.

Communications Minister Stephen Conroy didn't hold back, saying that Fletcher's claims were "embarrassing" and ignored a number of suburbs such as Kiama which were in coalition electorates.

"I reject the entire premise of the idiotic press release Mr Fletcher put out," Conroy said.