Key Points:

Maori seats in Parliament should be abolished and the ethnically justified basis for them is "repugnant" and amount to "reverse discrimination" under MMP, according to Business Roundtable-sponsored research.

But the report has left critics asking why having too many Maori in Parliament would be seen as a necessarily bad thing.

In a paper being released today, Canterbury University law professor Philip Joseph argues that under the mixed member proportional voting system Maori have achieved proportional representation without the need for separate seats.

Professor Joseph said putting aside the seven Maori seats, the 15 other Maori representatives in Parliament put it a little under 2 per cent short of reflecting the 14 per cent national population.

However, with the Maori seats the current parliamentary representation equated to 22 per cent.

The research said that would be fine if the MPs were all elected under MMP; it wasn't fair to "gift" seats to Maori based on ethnicity.

Political commentator Matt McCarten said Professor Joseph's argument was "ignorantly racist" because it seemed to suggest there was a strict quota of Maori MPs acceptable in Parliament.

"You didn't see a report when rich, white men were over-represented in Parliament. Now, it's suddenly become a concern because Maori might soon wield real influence."

Auckland University political scientist Ann Sullivan said just because Maori MPs claimed descent didn't mean they identified as Maori or were in Parliament to work on issues that affected the minority.