In February Senator Watt decided against assessing Top End Pastoral company's plans to bulldoze 2722 hectares of savanna at Claravale Station and Farm near the Daly River, north of Katherine in the Northern Territory.
Environment Centre NT, with its lawyers at Environmental Justice Australia, announced on Thursday it would challenge the decision in the Federal Court, seeking a judicial review of the minister's decision.
They argue the minister should have rejected the referral because it is only one stage of a three-stage clearing project which could see almost 6000 hectares of savanna cleared for crops.
They also argue the minister failed to consider impacts on threatened species including the freshwater sawfish, ghost bats, rainbow-coloured Gouldian finches and the red goshawk, Australia's rarest bird of prey.
Environment Centre NT said Australia's great northern savanna covered a third of the country and was the largest intact savanna ecosystem in the world.
In 2023 it was alleged the owners of Claravale Farm bulldozed land without appropriate permits in 2021, prompting a federal investigation but the matter was later settled out of court with the NT government.
Environment Centre NT Executive Director Dr Kirsty Howey said Senator Watt failed to do his job in greenlighting a massive deforestation proposal on land that's home to threatened species.
She hoped the court found the minister's decision was unlawful, leading to it being reassessed.
"We're facing a deforestation crisis here in the territory, with the bulldozers rolling in on the world's last intact tropical savanna, while the federal government looks away."
Environmental Justice Australia Senior Lawyer Nicola Silbert said it would be argued Senator Watt made key legal errors when he refused to assess the clearance plans.
"Given the scale of the bulldozing and the risks to threatened wildlife in this biodiversity hotspot, this case raises serious questions about whether Australia's nature laws are being properly applied."
The federal government said it was aware judicial review proceedings had commenced in the Federal Court relating to the Claravale Development Project.
"As this matter is before the court, it would not be appropriate to comment further," a spokesperson said.
The pastoral company has been contacted for comment.
