The National Party says after working on the roll-out of free-to-air digital television for at least the last three years, the government is still short on details.
The government announced on Thursday that digital free-to-air television will start transmitting from next year, with analogue transmission phased out in within 10 years.
National's broadcasting spokesperson, Georgina te Heuheu, says she wants more detail on how much digital television will cost individual households to access and taxpayers as a whole.
Broadcasting Minister, Steve Maharey, says local content will remain a strong part of the country's free-to-air mix.
But, the Consumers Institute says it will be difficult to make 18 free-to-air channels for a country the size of New Zealand work.
Consumers Institute chief executive, David Russell, says New Zealand has a population the size of an average overseas city, that is spread across two skinny islands. He says while the viewers will have more choice, the quality of that viewing is so far unknown.
The move will affect TVNZ, CanWest, Maori TV, the TAB and Radio New Zealand.
The broadcasters, who have forged an alliance called FreeView, have leased satellite space to make the conversion.
They will invest $75 million into establishing FreeView.
The government will invest $25 million and provide free access to digital frequencies, estimated to be worth $10 million.
CanWest chief executive, Brent Impey, says up to 18 channels have been set aside for free-to-air, with six for TVNZ, six for CanWest, and six for other broadcasters, possibly including regional stations.
Sky Television, which is in 42% of the nation's homes, is positive about its new rival, saying the changes should be beneficial to everyone.
Sky chief executive, John Fellet, says the evidence shows the introduction of free-to-air digital TV overseas has not slowed the growth of pay-TV operators like Sky.
The government expects to switch-off analogue TV between 2012 -