Te Tai Tokerau MP Kelvin Davis says it would be a "catastrophe" if Ngapuhi was sent to the back of the queue as Treaty Negotiations Minister Chris Finlayson prepares to go to Cabinet on Monday to decide whether to put the settlement on the shelf.
That decision will depend on whether two groups of hapu within Ngapuhi can agree on a body to represent them in negotations before then.
Although the Crown and one group of hapu - Te Kotahitanga - have agreed to a new model, the Tuhoronuku grouping has not.
Finlayson wrote to Tuhoronuku board in August warning if they did not agree by September 20 he would have little choice but to put Ngapuhi's settlement on hold to make space for other iwi - a step which would effectively ruin any chance of the biggest iwi reaching settlement by 2020.
He also warned he would have to reassess the mandate given to Tuhoronuku in 2014.
Unless the Tuhoronuku board can convince Finlayson they are at least close to agreeing after a last ditch meeting on Friday, it is likely to lose its mandate and Ngapuhi will lose the chance of progress on the settlement in the next few years.
I'm just going to get down on my hands and knees and pray that common sense breaks out. I could be praying for a long time.
Davis said it was make or break time for Ngapuhi.
"This week is one of the most crucial for Ngapuhi in the last eight years. It would set Ngapuhi right back and we could quite possibly go to the end of the queue. That would just be a disaster."
He said things were inches away from resolution.
"And I would just hate to see it turn to custard because our Ngapuhi leaders couldn't agree on those final few inches."
He said there was little he could do to prod things along and Finlayson had not asked them to get involved.
"I'm just going to get down on my hands and knees and pray that common sense breaks out. I could be praying for a long time."
In an open letter to Ngapuhi, chair Hone Sadler said it was regrettable that mandate problems continued to stymie the settlement's progress but it required clarity on its concerns before it could move on.
That included concerns it would fracture a one-iwi settlement into smaller hapu settlements, and the status of urban Maori and kuia and kaumatua on the settlement body.
Sadler has said legal action is possible if Finlayson removes its mandate.
Finlayson had hoped the two contesting groups of hapu within Ngapuhi had resolved their differences and agreed on the new model after working with each other resulted in the Marama Mai report.
Finlayson briefed Ngapuhi MPs this week, including Labour's Davis and Peeni Henare, NZ First MPs Pita Paraone, and National MP Shane Reti. Green MP Marama Davidson and NZ First's Ria Bond are also Ngapuhi but could not make the meeting.
The mandate given to Tuhoronuku in 2014 was challenged by the Te Kotahitanga hapu group in the Waitangi Tribunal which last year recommended a process more inclusive of the various hapu.
As a result Tuhoronuku and Te Kotahitanga worked together on the 'Maranga Mai' report which recommended a more hapu-driven model for negotiations.
That was approved by Finlayson - but failed to get the 75 per cent support needed in Tuhoronuku.