Minister of Treaty Negotiations Chris Finlayson says it is time for Ngāpuhi leader Sonny Tau to bow out and let younger talent take the helm of the tribe's affairs.
Mr Tau, the chair of the Ngāpuhi Rūnanga, was convicted last month of killing kereru and conspiring to pervert the course of justice.
He has been on leave from his job since October 2015.
There are also calls for him to resign coming from rūnanga trustees.
Mr Finlayson recently welcomed the efforts of opposing factions within Ngāpuhi to agree on a path towards treaty settlement, after hapū successfully challenged the mandate held by Tūhoronuku, the board formerly led by Mr Tau.
Mr Finlayson said there was a wealth of ability within Ngāpuhi, and Mr Tau should now step down and make way for it.
"I think in a gesture of statesmanship he should stand to one side," Mr Finlayson said.
"He should stop saying he has discussions with me, because he does not.
"Every person has their day in the sun, and then they should move on. It's my considered view that Sonny Tau should move on for the sake of his tribe. "
Three of the 11 rūnanga trustees have also spoken out against Mr Tau's continued leadership, in a letter to members of Ngāpuhi takiwa, or district bodies.
Mike Kake, Helene Leaf, and Te Rau Allen say Mr Tau's convictions directly affected his ability to do his job.
Mr Tau is serving a three-month sentence of community detention, with a 7pm curfew, and is required to wear an electronically-monitored ankle bracelet.
"From our perspective, the image of any Ngāpuhi leader attending hui of significance wearing an ankle bracelet is a serious matter, which raises concerns about the potential impact on the mana and credibility of our rūnanga and iwi," the trustees said.
However, the second conviction of conspiring to pervert the course of justice was by far the more serious, the trustees said.
"This conviction demonstrates an undermining of the New Zealand legal system. The head of that system is the Attorney-General, Chris Finlayson, who is also Minister for Treaty Negotiations.
"As Ngāpuhi prepares to enter settlement negotiations our rūnanga and iwi leadership must be beyond reproach," the trustees said in the letter.
They said the rūnanga also had to consider the way Mr Tau had conducted himself over the kereru affair.
Mr Tau had not told the trustees when he was first arrested in Invercargill, and left them unprepared to respond, they said.
"In his attempts to cover up his offending, his daughter's partner has also been convicted alongside him and this is not the type of example any of us want to set for Ngāpuhi," they said.
Mr Tau could not be reached for comment this afternoon.