Iwi leaders have told the government they'll see them in court over Māori rights to freshwater.
The leaders met Cabinet ministers in Ngāruawhāhia on Friday, where the politicians made it clear those rights were not up for debate.
Now the iwi leaders say they have no choice but to go to court, given the Government's unwillingness to negotiate with Māori on freshwater rights.
The Waitangi Tribunal and the Supreme Court have both acknowledged Māori have first rights to freshwater, but that has not been backed up by Government policy.
Ownership rights are at the heart of the debate about water allocation and management, but successive governments have failed to reach a position that satisfies Māori.
On Friday the Iwi Chairs Forum and government ministers met for the first time following a Cabinet decision not to pursue any water ownership rights for Māori.
While Environment Minister David Parker describes that meeting as amicable, his office has since been informed by senior forum leader Willie Te Aho that iwi are going back to court.
Mr Parker said he had no issue with any group using the courts to settle disagreements.
"As I said to the iwi chairs on Friday in New Zealand, any critic of any Government policy is always free to use the court process, so we're not going stop people doing that. We disagree with him but that's his right."
In the lead-up to the election the Labour Party campaigned on a royalty on the commercial consumption of water, which would include working with iwi to resolve Treaty water claims.
That policy died when Labour went into coalition with NZ First, which is vehemently opposed to Māori ownership rights.
NZ First leader and deputy prime minister, Winston Peters, said the Government was working its way through the issues.
"Well it's an ongoing discussion we're having, in wide consultation with the Labour Party and the Greens, and indeed the country.
"Look we're all part of this country, Māori, European, everyone from any other country who happens to be here legally, is all part of this issue and when we have decided what's in the best interests of every New Zealander, we'll let you know."
Co-chair of Labour's Māori caucus, Willie Jackson, said while the previous National-government held the view nobody owns the water, that is still a live debate for this government.
"No that's something that still needs to be discussed and it's been a big issue for the last couple of years, so it's certainly something we haven't come to at the moment."
Mr Te Aho is also criticising Mr Parker's proposed structure of Kahui Wai Māori - a wide-reaching Māori advisory group to consult the government, primarily, on water issues.
In his email to ministers he said the Forum wanted to appoint half of the group's representatives, and the Crown the other half.
Mr Parker has yet to respond to that proposal but does want to consult more widely than the last government.
Asked whether it was ever going to be possible to satisfy the iwi leaders on freshwater issues, Mr Parker said: "time will tell''.
This is yet another issue where coalition partners Labour and New Zealand First have to consider their original positions and try to reach a compromise that not only keeps faith with their supporters but is enough to seal the deal with Māori.
The previous government failed to make any ground in the last decade - Māori will now be looking to the courts for a favourable outcome, and an opportunity to break the political deadlock.