Key Points:

The Maori seats in Parliament became an issue for minor parties today and one said they were distorting the electoral system.

The Maori Party, which holds four of the seven seats and is aiming to win all of them in the election, wants the seats entrenched in law.

That would mean they could not be removed without a 75 per cent majority vote in Parliament.

At present they could be abolished with a simple 50 per cent majority vote.

The Green Party said today it supported the Maori Party's position.

MP Metiria Turei said general seats were entrenched, and she had drafted a member's bill to require any decision on the Maori seats to meet the same threshold.

National is embroiled in a controversy over the seats because it has a policy to eventually abolish them and has run into problems with the Maori Party because of that.

National's leader, John Key, confirmed yesterday he had told the Maori Party the policy would not be a bottom line in any negotiations after the election.

He had not previously said the policy was negotiable.

United Future leader Peter Dunne said today they were all missing the point.

"The continued existence of the Maori seats has long since gone past the bumper sticker slogans of race-based representation by opponents of the seats, or preserving the special place of Maori in the electoral system by supporters of the seats," he said.

"It is now an issue about totally distorting MMP and potentially perverting the will of the voters."

Mr Dunne said if current polling was an accurate reflection of voter intentions, the Maori Party was on track to win six, if not all seven, of the Maori electorate seats.

But the party was only polling between 2 per cent and 3 per cent of the party vote, which would entitle it to two or three seats.

"If this plays out at the ballot box, Parliament would have to grow by either four or five seats from 120 to 125 seats," he said.

"This overhang would result in either of the major parties having to cobble together a total of 63 rather than 61 seats to form a majority to govern."

Mr Dunne said if National's current polling became reality and it won 51 per cent of the party vote it would have 61 or 62 seats in Parliament.

"But with the potential overhang caused by the Maori seats, National would not be able to form a government," he said.

"Such a situation would be totally undemocratic and unacceptable.

"The fundamental tenet of representative democracy would be totally perverted. Put simply, the will of the majority would be thwarted."

Mr Dunne said the Maori Party should explain how the continued existence of the seats could justify that scenario.