Tukoroirangi Morgan has met with his lawyers after he failed to be re-elected to Waikato-Tainui's executive, Te Arataura.
An election of officers - including for his former position of Chair - was held on Sunday in Hopuhopu near Ngaruawahia.
Mr Morgan is contesting the decision by the chair of the meeting, the Maori King's representative, Greg Miller.
Nine of 10 members were elected based on a rule that candidates had to secure at least 33 marae votes.
Mr Morgan is challenging that, saying a high court verdict last year ruled that, in order to be elected, a candidate must receive more than half the total votes from marae which are present.
He says he's met that criteria and plans to filed an application for an urgent court hearing this week.