Prime Minister Helen Clark and National Party leader John Key are facing fresh criticism for refusing to take part in a televised campaign debate with the minor parties.

Their decision has led to TV3 cancelling the October 9 debate, which would have featured the leaders of all eight parties represented in Parliament.

The network is also considering whether to go ahead with its head-to-head debate featuring Clark and Key.

TVNZ is holding two head-to-head debates and a separate debate for minor party leaders.

The minor parties have severely criticised Clark and Key, and today independent observers did the same.

Richard Griffin, who was once former prime minister Jim Bolger’s chief press secretary, said National and Labour had always regarded the all-party debates as a chaotic circus.

“In virtually every sense, neither of the main parties has ever felt comfortable with the debate, nor do they believe they ever advance their cause during the debate,” he said on Radio New Zealand.

“Neither National nor Labour has accepted that proportional representation is really a game they want to play…but they’re prepared to play the game after the election when they use the minor parties as pawns.”

Gavin Ellis, former editor of the New Zealand Herald and now a lecturer at Auckland University, said elections were shifting towards presidential-style campaigns and the decision by the leaders of the two main parties was a consequence of that.

“Clark and Key clearly want to see this as a presidential race, flying in the face of the very purpose of MMP in the he process,” Ellis said.

Neither Mr Griffin nor Ellis appeared to believe Clark’s assertion that the decision was a result of discussions at chief of staff level.

“I regard that as sheer sophistry…these decisions aren’t made without the explicit approval of the two party leaders,” Ellis said.

Griffin said it was “nonsense” to suggest the decision had been made by the chiefs of staff.

Clark and Key says their head-to-head debates are the most important because there are only two candidates to lead the next government.