Winston Peters has slammed the selection of Mike Hosking to host TVNZ's election debates - saying he is right-leaning and a "wholly unsuitable" choice.

TVNZ head of current affairs John Gillespie has confirmed the Newstalk ZB and Seven Sharp host will present three debates in the run-in to the September 23 election.

Those will include two leaders' debates on August 31 and September 20 with Bill English and Jacinda Ardern, and a multi-party debate with other party leaders on September 8.

The debates will be simulcast on Newstalk ZB.

Peters said TVNZ needed to say who else they considered to host the debates.

"Or did they just call their favourite son and wave a dollar package at him," Peters said.

"It would be fair to say many New Zealanders are tired of his brand of broadcasting. This goes to the nub of the matter. At election time there is a standard of fairness and balance to be set by broadcasters - the choice of Mr Hosking breaks all those."

Peters also criticised the decision to hold two leaders' debates with Labour and National and relegating other parties to another debate.

Recent polling points to New Zealand First holding the balance of power after the election.

"TVNZ has decided on the main two debates with two parties, neither of which will have enough votes to govern alone. Are the TVNZ executives making these decisions without any knowledge of the political landscape in this country?" Peters said.

"For their education, we are now in an MMP environment and have been for over 20 years. It is no longer first past the post."

In the lead-up to the 2014 election Labour unsuccessfully pushed TVNZ to ditch Hosking as host of the election debates, with then leader David Cunliffe's staff compiling a dossier of examples of why he was unsuitable.

Hosking is a host on Newstalk ZB. Both the New Zealand Herald and Newstalk ZB are owned by NZME.