United Future leader Peter Dunne is calling for a public referendum on the Maori seats in Parliament.
A Royal Commission recommended in 1986 that the Maori seats should go when MMP voting was introduced.
Mr Dunne says the electoral system involves all New Zealanders, and it should not be up to just one group to decide whether one form of representation prevails.
He points to projections showing a rapid increase in Asian and Pacific populations over the next 20 years and says no-one is suggesting separate representation for those groups.
Mr Dunne says the Maori Party would benefit from being able to compete more openly, rather than being ghettoised into the Maori seats.