Nelson's Wakatu Incorporation is backing a Bill that would require land not used for the purpose it was originally taken for to be offered back to its original owners.
Chairperson Paul Morgan says the issues in Maori Party MP Te Ururoa Flavell's Public Works Act Amendment Bill are so important to Maori that they should be picked up for a full Government Bill.
He told Waatea News that Wakatu has had to go to court to stop government agencies and councils chipping away at its remaining estate.
He said the Bill actually accommodates the public good by leasing land - for instance, for roads - on a commercial basis.
Mr Morgan said Wakatu is also fighting a Crown attempt to hand over education land taken from it under the Public Works Act to another iwi to settle Treaty claims.