Helen Clark, New Zealand's prime minister, has promised a review of academic programmes aimed at ethnic groups after an opposition attack on university admission procedures that favour Maori students.
Don Brash, the National Party leader, criticised government policies in a "one law for all" assault on affirmative action.
Academics at New Zealand's two medical schools defended the selection process, saying more Maori doctors were essential to improve Maori health.
Mr Brash said that relaxed entry level standards could lead to a perception that Maori had lesser qualifications. He warned universities: "If you want funding, you can't have racially based systems."
But universities countered any implication that the qualification bar might be racially based. Stuart McCutcheon, chairman of the New Zealand Vice-Chancellors' Committee, said: "The standards of assessment in each discipline are the same for all students."
Auckland and Otago medical schools reserve places for Maori and Pacific students - Auckland through an admissions scheme, Otago on a more informal basis.
Philippa Howden-Chapman, associate professor of public health at Otago, said high exam grades alone were not a predictor of good doctors. "The medical workforce has more money invested in it by the state than any other, so you want to make sure you have people who reflect their community and can successfully work in it," she said.
Research had shown that having more Maori doctors was likely to result in improved health outcomes for Maori, she said.
A survey of GPs shows that only 1.5 per cent are Maori, although Maori make up 15 per cent of the population and die, on average, up to ten years earlier than non-Maori.