Labour leader Andrew Little has proposed looking at giving Maori greater self-governance, possibly including the ability to make some of their own laws.
Mr Little made the comments yesterday, referring to a Waitangi Tribunal finding last year that Northland Maori did not cede their sovereignty when signing the Treaty.
Prime Minister John Key was criticised by elders at Waitangi for dismissing that report. Mr Little said the Waitangi Tribunal report found Maori should be able to make their own laws on matters affecting them. While that would be "highly problematic" he said it should be looked at.
Mr Little acknowledged it could concern some New Zealanders. "The fear is always that these things turn into a 'they are getting special privilege' or 'they are getting a control we would never be able to have'. We have to be sensitive to that, but we've also got to understand for iwi now and those who have had their settlements and developed their own economic base, there are some things we might want to say they can be responsible for that is consistent with historical obligations."
He said it was time to look at what would happen after the settlements were completed.
He said some Native American tribes had law-making powers over their territories in the United States where recognised tribes were exempt from some laws - including taxation - and could create their own laws in many areas. Mr Little said allowing separate law-making was "highly problematic".
"But we shouldn't be so dismissive of any claim by iwi over what they do. We do have to function as a nation-state and we don't want to compromise that. But let's have a look at it."
Mr Key said allowing some iwi the ability to make their own law would be "divisive" and he did not support the suggestion.
Mr Little also pinned his flag to the republican tent yesterday, saying New Zealand should move to sever the apron strings with the monarchy before Australia.
Mr Little said he supported changing the flag but it was mere "window dressing" and should be done as part of wider constitutional change - change which also included ditching the Queen as the head of state.
"If we want to assert our independence, changing the flag won't do it. Changing our head of state will."
New Zealand will vote on whether to change the flag in a referendum next year. A second referendum will be held on the new flag if the vote is for change.
Mr Key made it clear changing the flag was his limit as far as a nudge toward republicanism went, describing himself as "the biggest constitutional monarchist you'll meet".
"I believe in the Queen as head of state and I don't think ... having a president does anything for us other than being a very expensive exercise, one that wouldn't work terribly well."