Iwi leaders have been invited to nominate people to join the new body but have so far declined.
The new group will have input into cabinet papers before they are submitted to cabinet and have their own secretariat based in the Ministry for the Environment.
The boycott by iwi leaders in freshwater policy highlights an important evolution in Treaty of Waitangi relationships, especially in relation to the concept of partnership.
Who is the Crown's treaty partner? Should the Crown get to fashion the shape of the partner? What sort of standing should they have?
And was it reasonable for the new Government to have abandoned the freshwater iwi leaders group in the way it has?
National found it easy to engage with iwi leaders as the treaty partner because it was a natural continuation from historic treaty settlements – over 60 settlements acts in 25 years - in which statutory relationships were established between the Crown and iwi.
There was no reason for the Government not to use the same bodies to extend the relationships beyond settlement.
Iwi leaders may once have been labelled 'the Brown Table" by Labour's urban activists and Winston Peters when he opposed the fisheries settlement, but after the treaty settlements process, they cannot be accused of having no mandate.
The Maori Party in its early days used to describe itself as "the treaty partner" but realised soon enough that National saw iwi leaders as the partner, and were being brought into the inner sanctum of decision-making.
In the competition for influence between pan-Maori organisations such as the Maori Council and iwi, National came down firmly on the side of iwi fundamentalists.
National gave them respect.
Labour and New Zealand First's coolness towards the Iwi Chairs Forum suggests it interpreted the close relationship between National and iwi leaders as an act of political allegiance rather than political pragmatism.
Whatever has motivated the Government, it is clear that it is unwilling to give the forum a special status above advocacy or activist groups.
The iconic image of veteran activist Titewhai Harawira at the cabinet table with Jacinda Ardern symbolised the shift.
But the fact is when it comes to dealing with Maori interests in water on a catchment by catchment basis, as the David Parker plan will, the regional councils will not be dealing with the bitterly divided Maori Council or the even more bitterly divided Maori Women's Welfare League. It is going to be iwi of the area and the hapu who own land.
The vexed issue of the treaty partnership was highlighted in a broader context this week when Maori Crown Relations Minister Kelvin Davis released the cabinet paper giving some details about the new Government agency he is creating to oversee the whole gamut of Crown and Maori engagement.
And it again confirms a Government downgrade of iwi leadership groups as treaty partners.
In it, he says that iwi and hapu should be treated as treaty partners, but that did not apply to the institution of the Iwi Chairs Forum - several hundred iwi leaders with whom National engaged regularly and in which the size of the grouping gave them political strength.
"The Crown's responsibilities are to all Maori, not just the forum," he said.
The agency will be set up very quickly, by order in council, avoiding the need for legislation.
It was originally to have been called the Office for Crown Maori Partnership but that was vetoed by New Zealand First, although that is not mentioned in the cabinet paper.
Davis says he ruled out the term partnership "because we are not at a point of being able to declare that we are there yet."
The fact that the Winston Peters does not accept the concept of partnership as set out in 1987 Lands case appears not to be an insurmountable difficulty for the Government.
One of the primary aims of the new agency will be to make the Crown a better treaty partner. That was one of the consistent messages Davis heard from consultation hui he held.
For a small agency sitting within the Ministry of Justice, it will have a hugely ambitious brief in controversial areas.
It will be responsible for contemporary treaty claims such as flora and fauna, it will help run major events such as Waitangi Day, and it will have an interest in constitutional changes.
It will work across the public sector to advise on their Maori engagement policies and practices. It will advise Government departments how to engage, when to engage, and which iwi or groups to engage with.
And, rather like an ERO, it will review the performance of Government departments in their engagement.
Replacing what was an organic and ad hoc approach by Government agencies' engagement with Maori, the new agency will become the gatekeeper and controller.
At best it will provide a consistent approach. At worst it will act as a straitjacket on Crown and Maori relations.
