In December, the Kiingitanga called a nationwide hui over fears of the coalition government's plans for Māori.
Iwi across the country are set to converge at Tūrangawaewae Marae in Ngāruawāhia this Saturday, to work out a unified response to the coalition government's policies.
Thousands are expected to attend the national hui, Taakiri Tuu Te Kotahitanga, Taakiri Tuu te Mana Motuhake, convened by the Māori king, Tuuheitia Pootatau Te Wherowhero VII.
The invite was extended to iwi in December last year, following the 165th anniversary of the Kiingitanga movement.
RNZ understand the PM and Kiingi Tuuheitia are meeting on Monday morning. A press secretary for Luxon has confirmed they will meet but have not given a time.
Ariki and Leaders - including Te Ariki Taa Tumu Te Heuheu and Ratana Tumuaki, Manuao Te Kohamutunga Tamou - supported the call for a national hui and agreed the Crown must be a responsible Treaty partner and unify, not divide the nation.
Kiingitanga chief of staff Ngira Simmonds said rangatira from across the country highlighted a need to unify the nation and ensure all voices were heard in holding the government to account.
The divisive rhetoric used during the election campaign and policy targeting Te Tiriti o Waitangi and te reo Māori was offensive to Māori and non-Māori, Simmonds said.
"There's strong opposition to the government's statements on the Treaty of Waitangi, which could undermine decades of hard-fought justice and equality for our nation," he said.
"Now is the time for kotahitanga and focusing on what we have in common."
Waikato-Tainui will host the masses set to attend the hui and just last week the iwi filed proceedings at the High Court in Wellington against the Crown.
Executive chair Tukoroirangi Morgan said the iwi were seeking declarations to affirm the rights and interests of Waikato-Tainui and the corresponding obligations of the Crown.
"We are concerned about recent statements that have been made by Ministers within Cabinet and others within the coalition government (regarding prospective Crown decisions and actions) which would be in direct conflict with the Crown's commitments and related obligations to Waikato-Tainui," he said.
Waikato Tainui said the Crown had an obligation to protect te reo Māori under Te Ture mō te Reo Maaori 2016, and the proceedings at the High Court aimed to address immediate concerns on those matters that were now under threat.
"We do this to protect what has been hard-fought, as we will not have the rights and interests of Waikato-Tainui or the relationship between Waikato-Tainui and the Crown undermined," Morgan said.
Many iwi have met ahead of the hui to finalise key messages and organise travel arrangements for whaanau wanting to attend.
The Office of the Kiingitanga and Iwi of Tainui Waka said more than 3000 guests would attend the hui and thousands more were expected to follow discussions online.
Ngira Simmonds said the hui would be positive and future focused.
"We have invited people to lay down their koorero and their aspirations and ideas for mana motuhake and upholding Te Tiriti o Waitangi.
"As signalled at Koroneihana last year, mana motuhake is an approach offering solutions and hope for the future of our nation. Māori can lead for all, and we are prepared to do that.
"The hui is open to all and will be conducted in accordance with tikanga."
The hui at Turangawaewae will be one of several opportunities for people to express their views and explore potential solutions.
