The Department of Conservation's (DoC) plan to cull Himalayan tahr has been described as unlawful and unfair.
A judicial review hearing has been held at the High Court in Wellington against DoC's culling programme of the goat-like animals in the South Island.
It is hoped the plan would reduce numbers to about 10,000 - which would hugely benefit native tussocks and landscapes.
However, the Tahr Foundation, which brought the court case, believes hunters were not consulted.
It said tourism operators were opposing the cull because they stand to lose significant income and the cull would put more than 500 jobs on the line.
Jack Hodder QC, representing the foundation, told a packed High Court on Wednesday the cull programme was unlawful.
"The foundation says that that 2020-21 operational plan should be quashed because it is unlawful - because it sets targets for the management units defined in the 1993 control plan.
"Those plans have new features compared to previous plans - they have a much increased overall target ... and they include targeting of bull tahr in national parks ... that as evidence has particular significance for the commercial and guided hunting industry," he said.
He described an absence of "meaningful consultation."
Hodder said the targets needed to be reconsidered so that hunters and members could be properly consulted.
Speaking for the Crown, David Laurenson QC said tahr must be controlled and acknowledged hunters played a part in that.
However, he said DOC had taken official control because it could cull a larger number than the hunters.
He denied DOC had completely disregarded the views of the foundation and hunters, saying their views were widely known and thought about during the implementation of the cull programme.
Justice Dobson will reserve his decision, however, RNZ understands a written decision could be published as early as Friday.