Northland's Ngati Hine leaders say they will always be part of Ngaphui - but they intend to enforce their legal right to break away from the Ngapuhi runanga.
Ngati Hine have gone to the Maori Appellate Court in Whangarei to argue the runanga is wrong to claim it has a mandate to represent Ngati Hine in Treaty settlements.
The sub-tribe has the right under the Fisheries Act to withdraw from the Ngapuhi runanga, and control its own share of the iwi's fisheries assets .
It says the Ngapuhi runanga has been stalling the separation because it can not claim a mandate for all of Ngapuhi, to drive the iwi's land claims, if Ngati Hine pulls out.
Lawyer for Ngati Hine Mike Doogan says the issue is with the runanga - not the iwi.
The case went before the Maori Appellate Court on Tuesday and the judges have reserved their decision.