The group holding the mandate to negotiate the massive Ngapuhi Treaty settlement is on the verge of losing it.
Tension has given way to open rebellion in the ranks of Tuhoronuku - the board set up by Ngapuhi leader Sonny Tau.
Tuhoronuku chair Hone Sadler has told the government the board cannot meet a 20 September deadline to commit to sharing power with opposing hapu groups.
But three Tuhoronuku trustees who have been working with hapu to resolve the long-running row over representation have emailed all board members urging them to commit by Friday.
Audit and risk committee chair Erin Shanks said stalling by Tuhoronuku's leadership had put the board on the brink of losing its place in the Crown's negotiations queue for next year - and the mandate itself.
The time for stand-offs in Ngapuhi was over, Mr Shanks said.
"If the mandate is withdrawn, essentially the body that the Crown has agreed to negotiate the settlement with is in limbo.
"They will have nobody to negotiate with. "
For that to happen was a very sad state of affairs, he said.
Treaty Negotiations Minister Chris Finlayson asked both factions in the long-running mandate dispute to let him know by 20 September if they would adopt the recommendations of the Maranga Mai report, the result of months of work by a joint working party.
"The Crown expects the Maranga Mai recommendations to be implemented in full," he said.
"If they are not, then the Crown would have to assess whether it continues to recognise [Tuhoronuku's] mandate. "
The hapu alliance agreed to the recommendations, but said there were still some sticking points to work through.
Mr Finlayson said there would need to be concerted work over the next four months to transition from Tuhoronuku to a new Ngapuhi mandate authority outlined in Maranga Mai.
"For Ngapuhi to be on the work programme [for Treaty negotiations] next year, the evolved mandate structure should be set up by 9 December," he said.
Mr Sadler said the Tuhoronuku Board could not meet the 20 September deadline because trustees had not had enough time to digest the Maranga Mai report.
They had four outstanding issues to discuss, including urban and kaumatua representation, he said.
The Minister's response was frosty.
"I understand you are able to call a meeting of the Tuhoronuku Board before [20 September] but have chosen not to," he wrote.
"That suggests the board is not committed to ensuring Ngapuhi is in the Treaty settlement work programme to achieve and agreement in principle in 2017.
"I will take that message into discussions with my colleagues," Mr Finlayson wrote.
Erin Shanks and two other trustees asked fellow trustees to support an urgent motion circulated by email this week, resolving to meet the Minister's deadline and commit to adopting the Maranga Mai recommendations by email - by next Friday.
Hapu representatives have told RNZ if Tuhoronuku collapses, and the mandate is withdrawn, they may seek to enter negotiation with the Crown as hapu or groupings of hapu.
They have had indications that could be acceptable to the government, they said.
Sonny Tau's future in question
Hone Sadler - the Auckland academic who has been a strong supporter of Mr Tau - took over as Tuhoronuku chair last year, after Mr Tau was caught with dead kereru at Invercargill airport.
Sonny Tau told kaumatua, the runanga and the board at the time, that he did not shoot the birds but was taking the rap for his son-in-law and taking them home as gifts for kaumatua.
Both men later admitted the story was a fabrication and Mr Tau was convicted of killing the birds and conspiring to pervert the course of justice.
Members of Tuhoronuku obtained the police summary of facts from the case and the judge's sentencing comments, and circulated both documents this week within Ngapuhi.
They said the records showed Mr Tau misled Ngapuhi and Ngai Tahu about his role in the kereru incident, and his dishonesty conviction made him unfit for office.
Lawyer Moana Tuwhare, a Tuhoronuku trustee who has led the board's efforts to reconcile with the hapu alliance, filed a motion for the next board meeting to consider Mr Tau's future.
Her email to members read: "As a board I think we need to review this latest information that has come to hand regarding [what]Sonny told our board in explanation of his offending last year. This is a serious matter that has obvious implications for our Trust and our future."