The Kingitanga wants to lead discussions among iwi on constitutional reform - and it will put the plan to them as they descend on Turangawaewae Marae today for anniversary celebrations.
If it materialises it would be the first clear example of what the 150-year-old movement now stands for under its leader King Tuheitia.
Tainui executive chairman Tuku Morgan said Australian Prime Minister Kevin Rudd's support of moving towards a republic had prompted the Kingitanga to consider what a change, if it happened in this country, would mean for Maori.
If New Zealand decided to explore that option, Maori shouldn't be caught flat-footed, he said.
"For that reason we need to begin now to build a constitution that better reflects what we want and not be an afterthought if the country goes down that track.
"We want to drive this for Maori. The Kingitanga affords us that opportunity and we're going to put it to the motu (country) while they're here."
Ensuring the movement - which was formed to stop the loss of land and halt bloodshed among tribes - remained relevant this century remained critical as Treaty of Waitangi claims were settled, he said.
But so far, aside from outlining education as a platform, the movement's spokespeople for King Tuheitia have not articulated what the future direction is now.
Mr Morgan said that was a fair criticism. "Maori have to unite on key issues. Clearly what we don't want to get to, is a movement that can't move. The Kingitanga has to be adept and skilful at moving with the times.
"We have to take a more pro-active stand."
There was the capacity for the issue to lead on to other social issues such as protecting families against domestic violence.
Waikato University academic Tom Roa said questions of relevancy and growth were questions the tribe was asking itself every day.
But the Kingitanga belonged to the country's iwi and tribal leaders needed to take more of a hand in shaping the movement's future. It was a low-key start to the five-day anniversary celebrations yesterday.
About 500 gathered with pictures of deceased loved ones in the late afternoon at the country's largest marae. The kawe mate day is set aside for remembering Tainui's dead.