New Zealand could be "rocked constitutionally" in a Waitangi Tribunal hearing starting today with the country's largest tribe, Ngapuhi, arguing they never ceded sovereignty to the Crown.

The Northland iwi of 122,000 people will argue it was and still is a self-governing state within New Zealand.

It is the first time that the standing of the 1840 Treaty of Waitangi has been measured against the 1835 Declaration of Independence created by 34 northern chiefs of the Confederation of United Tribes. "We didn't cede our sovereignty, and if we did, we didn't do it to become paupers in our own land," Haami Piripi, chairman of the Kaitaia-based Te Runanga o Te Rarawa, said.

Although the biggest tribe, and the original host of the Treaty signing, Ngapuhi is the last to have its day before the tribunal.

"There is more opportunity than danger. I think it must rock the nation constitutionally."

Nothing existed that showed Ngapuhi ceded sovereignty. "We never ever saw an English version of the treaty and we never signed one."

Known as Te Paparahi o Te Raki or the Northland Inquiry, the hearings involve more than 1200 claims involving everything unheard north of the Auckland Harbour Bridge.

The tribunal will hear it in two stages with the first part beginning today with four weeks of hearings on the issue of sovereignty, the Declaration and the Treaty.

Hearings on claims are expected to take four to six years, but legal sources say it is likely the tribunal will issue a groundbreaking constitutional interim report by the end of this year.

The witness list includes some of Northland's most prominent names, including former Maori Council head Sir Graham Latimer, leading members of the powerful Henare family and the Harawiras.

Matriarch Titewhai Harawira and her son MP Hone Harawira are expected to speak at the hearing.

Mr Piripi said Maori had occupied the area for up to 2000 years and had governed themselves for much of the time. The tribunal would allow them to reassert this.

"It is a huge event historically for our sovereign status to be usurped by another. We need to re-examine the process by which this occurred."

New Zealand could prove to be built on a fairytale.

- © Fairfax NZ News