Opposition parties are accusing the Government of abandoning public service television broadcasting with the demise of TVNZ 7.
The channel, available on the Freeview digital platform and Sky TV, will stop broadcasting in June 2012.
Television New Zealand chief executive Rick Ellis says he asked the Government for renewed funding for the channel, but this was turned down.
Mr Ellis says 20 to 30 positions could be jeopardised, though he hopes many of the staff will be placed elsewhere in TVNZ.
The opposition says the loss of TVNZ 7 means Maori Television will be the only channel with a public service focus.
The Green Party says the Government does not believe in public service television and both the Greens and Labour say it is clear that having TVNZ as a purely commercial broadcaster shows it is being readied for sale.
But Broadcasting Minister Jonathan Coleman rejects this, calling it a wild conspiracy theory.
He says the Government's new stance on funding of public service television is that it will fund content, rather than channels.
Part-time Auckland TV director Myles Thomas has launched a Facebook campaign and online petition in support of TVNZ 7.
Mr Thomas says the programmes on the channel are intelligent and innovative and such programme is not available on commercial television.
