Iwi in the top of the South Island are disappointed the government has allocated $3.6 million of taxpayer funds to appeal the High Court's forthcoming decision in the Nelson Tenths case.
The Supreme Court ruled in 2017 that the government must honour a land deal struck in the 1840s between the New Zealand Company and Māori - but it has not yet been resolved.
Wakatū Incorporation chief executive Kerensa Johnston said it was incredibly disappointing funding has been allocated to continue fighting the case, rather than resolve it.
"Planning an appeal before the decision is released risks undermining the process and is a deeply disheartening approach."
The funding is designated for Te Arawhiti, the Office for Māori Crown Relations, and follows $5m being allocated last year, to contest the Māori customary owners' claims in court.
In the 1840s, Māori landowners around Nelson sold 151,000 acres of land to the New Zealand Company on the condition that 10 percent of their land would be reserved for Māori in perpetuity.
That agreement was never upheld. Rather than setting aside 15,100 acres, the Crown reserved less than 3000 acres.
Johnston said it had been a prolonged struggle for justice.
"It is particularly disappointing that the Office for Māori-Crown Relations, which was set up to foster good faith engagement with Māori, is instead funding legal battles against us."
She said Māori customary owners expected the government to honour the Supreme Court ruling.
Wakatū Incorporation had sought to meet with the responsible ministers over the years to resolve the case, including a meeting with the new coalition government, but the offers had been refused.
Johnston said the organisation had requested a meeting with Attorney-General Judith Collins KC to discuss a positive resolution of this case.
The Attorney-General's office has been approached for comment.