Greater sovereignty for Maori or a dangerous path towards separatism?
That is the latest political spat between the Prime Minister and the Labour leader, following comments made by Andrew Little at Waitangi.
At the end of last year the Waitangi Tribunal found Maori leaders did not cede sovereignty when they signed the Treaty of Waitangi.
The Tribunal said rangatira agreed to share power with the British Crown, but did not give up the right to make and enforce laws in their lands.
In response, Mr Key said that was a divisive way of looking at things.
"The Crown's view is that sovereignty was ceded in 1840 but ceded to a modern New Zealand that was built for all New Zealanders."
He said he would not support any form of self-rule for Maori.
That prompted accusations from Andrew Little about a lack of leadership, saying although it was natural for politicians to fear a voter backlash, leaders should face up to difficult issues.
"We already have things like co-governance of the Waikato River and Lake Lake Waikaremoana and those are forms of you might say sovereignty.
"If that's the sort of thing they're looking at why wouldn't we say alright, let's sit down and talk about what that means and what that looks like."
Mr Key said that would be taking New Zealand down a path of separatism.
"And once you do that it's a slippery slope because you'll get lots of people who will argue when it's convenient for them that gives them unilateral decision making rights in certain areas.
"I can't see why New Zealanders would support that."
But Mr Little said the Prime Minister's accusation that Labour was heading towards separatism was disrespectful.
Mr Little said he was not calling for separate powers for Maori, and the debate was important to those involved.
"It's not beyond us to sit down with Maori under the Treaty of Waitangi and say 'yip, so you've got this and this is the way it is now and how can we make this work,' it preserves the institutions and the democracy that we are."
New Zealand First leader Winston Peters said accusing Labour of being separatist was rich coming from a Prime Minister whose Government signed a deal with Tuhoe that laid out a path for co-management, with the iwi taking more-and-more control over time.
"Well that's quite amazing because that's the record since Mr Key has become the Prime Minister - he's caved in on a whole lot of issues."
Mr Key insisted the Tuhoe deal was not separatist.
"That is co-governance where you've got a scenario where there's input by statute if you like, of a number of different parties but they come together to make decisions.
"That's quite different from the independent state of Northland, or something else."
Chairman of Nga Puhi runanga Sonny Tau said the word sovereignty had negative connotations, and was used to invoke images of separatism.
But putting that aside, Mr Tau said it would be a good time to start talking about Maori taking greater responsibility for their own affairs.
"And I think we can do that in little pockets, I don't think that iwi is of a mind to go and ask the Government to vacate the Beehive and do that, I think we're not as silly as that.
"What we need to do is to have the conversation."