Ngai Tahu filed a late Waitangi Tribunal claim last night in response to what it called a "significant threat" to its 1998 settlement.
The application was made within hours of the midnight deadline for historical claims, imposed in December 2006.
Chairman (kaiwhakahaere) Mark Solomon said the claim was made to safeguard the future of Ngai Tahu whanui.
"The Crown continues to threaten the integrity of the Ngai Tahu settlement. Te Runanga o Ngai Tahu is compelled to lodge a claim before the passing of the imposed deadline due to the uncertainty of the political environment we find ourselves operating in today," he said.
An example of this threat was the Government's emissions trading scheme (ETS), he said.
"This represents a significant threat to both the integrity and finality of our settlement," Solomon said.
The legislation would "literally wipe tens of millions of dollars off the value of the forestry assets we received as part of our settlement".
"The ETS will undermine our settlement and unwind the very purpose of the settlement that we set out to achieve over the lives of many generations," he said.
The scheme the Government's flagship environmental policy is expected to be passed by Parliament before this year's election.
However, officials have already warned it could cost taxpayers hundreds of millions of dollars in payments to iwi.
A Ministry of Agriculture and Forestry report obtained by The Press last month suggested the scheme could leave the Crown open to substantial claims because the value of land handed to iwi under Treaty of Waitangi settlements could substantially decrease.
Solomon said the new Ngai Tahu claim focused on four areas: environmental resources, culture (tikanga and language), post-1992 losses and settlement breaches.
"It is our claim that the Government has failed to recognise and protect existing rights and historic interests in the area of environmental resources and our culture, tikanga and language that were not expressly included in our 1998 settlement," Solomon said.
"This claim is an insurance policy to ensure that our settlement remains final and we can protect what we have."
The head of Canterbury University's School of Maori and Indigenous Studies, Dr Rawiri Taonui, said the claim was a significant move.
"One of the things that's been quite disturbing about the deadline issue is the resounding silence from tribes that have already reached settlements," he said. "Ngai Tahu is the first to stand up and say, `There's something not quite right about this process', so hats off to them."
He said the threat posed by the ETS to forestry was of concern nationwide.
Another issue could be over future access to natural resources such as coal.
Tribes were currently not allowed to claim ownership of resources they did not use when the treaty was signed in 1840, he said.
However, international rulings in countries such as Canada and South Africa indicated this could change, but last night's deadline would effectively cut off all claims of that nature, he said.
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