Maori Party co-leader Pita Sharples says future political representation for Maori could be jeopardised by the dispute involving Te Tai Tokerau MP Hone Harawira.
The party's disciplinary committee will this week hear a complaint that Mr Harawira has brought the party into disrepute.
Maori Party whip Te Ururoa Flavell has laid a complaint following comments Mr Harawira made in a newspaper article in which he said voters were abandoning the party because it was coming off the rails and getting too close to the National Government.
Events at Waitangi to commemorate the signing of the Treay of Waitangi at the weekend increased tensions, with Mr Harawira giving a 'state of the nation' speech an hour before Dr Sharples was due to deliver his.
Dr Sharples says he views that as a direct challenge, adding that if Mr Harawira can not abide by caucus rules, he has no future with the party.
He says it is a critical time for the party and the future of Maori politics.
Meanwhile, Mr Harawira says only the people of Te Tai Tokerau should determine whether he needs to shape up or ship out.
He says he does not want to enter into a war over the comments by Dr Sharples, but as an electorate MP he has the right to speak out for his people.
He says he has been making very strong comments about the state of the Maori nation since he was young and he is not about to stop now.
Mr Harawira told Morning Report that he has been speaking at Waitangi for at least 10 years and did not know Dr Sharples was speaking.
He said he accepts Dr Sharples is the leader. But Mr Harawira refused to say whether he will stick to caucus rules or leave the party.
Electorate stands by Harawira
The Te Tai Tokerau electorate committee says it will stand by Mr Harawira MP should he be thrown out of the Maori Party.
Electorate chair Lisa McNab told Nine to Noon that Te Tai Tokerau wants the matter solved outside of the committee using Maori protocol.
She says the electorate has supported Mr Harawira in the past and will "definitely continue" to support him in the future.
Ms McNab also said the national executive of the Maori Party has become too far removed from Maori in the communities that it represents and the issues that Mr Harawira is raising.