A Ngapuhi leader is calling for a nine per cent economic development tax to be levied on everyone living inside the iwi's boundary as part of its treaty claim.
Matarahurahu hapu chairman David Rankin said the proposed flat tax rate, which would be administered by the Inland Revenue Department, would "pull Ngapuhi out of a depressed state" and ultimately benefit the entire region.
He would like it to fund social and economic development projects such as aquaculture programmes, and make Ngapuhi as prosperous as iwi like Ngai Tahu and Tainui, which benefit from rich resources in their regions, he said.
"We are a larger population but with very limited resources. Most of our resources actually disappeared before the treaty - we would be the poorest tribe in the country, resources wise."
While the proposal was still in the discussion stage, such a tax would be nothing new to Ngapuhi, he said.
"During the times of Hone Heke, every ship that came into the Bay of Islands he taxed them, so this is nothing new to us as a people."
The Northland iwi of 122,000 people says it never ceded sovereignty when chiefs signed the Treaty of Waitangi in 1840.
Hearings on the issue of sovereignty, the declaration and the treaty are expected to last another week.
Mr Rankin promised to withdraw his hapu's consent for the claim if the proposed tax was not achieved.
Since then, he had received much support for the initiative, particularly from Tuhoe, he said.
However, there had also been "one or two" members of the Ngapuhi Runanga, who administer the claim, who expressed their strong opposition and threatened to bar Mr Rankin from speaking at Waitangi Tribunal hearings.
AUT history professor Paul Moon said the proposed tax was not feasible unless Ngapuhi gained sovereignty.
"The right to tax is a sovereign right and unless Ngapuhi suddenly acquires that sort of sovereign authority it simply won't be in a position to let any taxes.
"It would require massive readjustment and it would lead to all sorts of problems as far as the tax system is concerned. If they are interested in economic development, they'll have to look elsewhere," he said.
While there might be historical validity to Ngapuhi's sovereignty claim, constitutionally there was not, he said.
"The sovereign claim is largely a symbolic gesture. It would be very hard, I imagine, to find people to say hand on heart 'we believe we're going to be 100 per cent successful with this claim'."