Abolishing the Maori seats would rip the country apart and attract "hikois from hell", John Key said.
Speaking to the Herald last week before the release of Nicky Hager's book Dirty Politics, the Prime Minister said that while it remained National Party policy to abolish the seats, even if he had enough numbers to do so, he would abolish them only with the agreement of Maori.
"It would divide the nation," he told the Herald's Hot Seat series . "Despite the fact that a lot of people say they don't like it and they were there for a particular reason, actually it would be an incredibly divisive thing to do to New Zealand and New Zealanders."
"Do you really want to rip a country apart? I'll tell you what would happen - hikois from hell."
Whether you were on the Maori roll or the general roll everyone got two votes.
While abolishing the seats has been long-standing policy for National, Act and United Future policy, the Maori Party's confidence and supply agreement with National saw it parked as an active issue. But even if the Maori Party were not in the next Parliament, Mr Key has in effect protected them.
Mr Key also indicated he would be receptive to the flexi-superannuation proposal of United Future leader Peter Dunne in any third term.
Flexi-super would allow people to take super earlier than the present age of 65 but at a lower rate or to wait longer for it and get more.
"Intellectually I am actually more than comfortable with that," Mr Key said. "We are quite comfortable with that. And actually there is quite a lot of logic," he said.
But it would not alter the cost to the taxpayer and he said it would not impact on his pledge to resign if the age of superannuation was raised above 65.
That pledge would remain for any third term or even any fourth term, he said.
He first made the pledge in 2008 when Labour began saying that National had a hidden agenda to raise the age of superannuation.
"I do think in the six years I have been there, what I say is what I mean. I am always happy to make a case to say 'look the position has changed' but I was really, really strong on that stuff."
He also believed superannuation was still affordable in its present form.
"The scheme at its maximum cost runs out to about 7 per cent or 7.5 per cent of GDP. That's still below almost all the countries that are raising their age of super. I am not so convinced it is this massive issue we all think."
Mr Key also discussed his next cabinet, should he be returned to power.
Deputy Prime Minister Bill English would remain Finance Minister as long as he wanted it. He indicated Paula Bennett would be in for a change after six years as Minister of Social Development, possible more commercially focused.
He said she had done an outstanding job in welfare.
"She would be in for a big portfolio but what it is I don't know," he said but indicated it was unlikely to be health.
"She is quite keen to display that she has got broader credentials than maybe just the social sector."
He also said that if Health Minister Tony Ryall had stayed on, he would have shifted him out of health.
The interview was conducted on August 12.
THE VIDEO SERIES SO FAR
Hone Harawira and Laila Harre, Internet-Mana
Colin Craig, Conservatives
Jamie Whyte, Act
Peter Dunne, United Future
Te Ururoa Flavell, Maori Party
Russel Norman and Metiria Turei, Greens
David Cunliffe, Labour