Graeme Samuel, the former Australian Competition and Consumer Commission chairman who led a review of national environmental laws in 2020, said the legal framework was failing to stop extinctions but a comprehensive redraft of the laws would not happen overnight.

"Just sit and wait, take a chill pill," Professor Samuel told a parliamentary inquiry into the extinction crisis on Wednesday.

"I think you will find that that what we're going to get will satisfy all their aspirations as set out in the Nature Positive Plan that the minister announced some time ago."

He was also highly critical of "negative publicity" from stakeholders in Western Australia, including the mining industry, on the government's environmental law reform agenda.

Environment Minister Tanya Plibersek announced on Tuesday the establishment of Australia's first national, independent Environment Protection Agency along with an information and data body called Environment Information Australia.

While conservation groups welcomed the move to boost compliance, they were also quick to point out the announcement was not accompanied by a reworked Environment Protection and Biodiversity Conservation Act.

The 1999 act is the nation's overarching environmental legislation intended to protect nature and was described by Professor Samuel as an "abysmal failure" during the hearing on Wednesday.

Australian Marine Conservation Society campaign manager Alexia Wellbelove called on the government to lay down a timeline for refreshed environmental laws before the next election.

Otherwise, she said the new cop on the beat would be undertaking compliance under a legal framework that was "reinforcing a trajectory of decline".

"That is not sufficient to meet our commitments for no new extinctions, it doesn't deal with the climate crisis, it doesn't stop the reef from bleaching," she told the inquiry.

Labor senator Karen Grogan thanked the environmental groups for their contributions but said reforming the environmental protection act was highly complex.

She said "barrelling ahead" without full consultation would result in legislation "dying on the floor of the senate".

"If that's what you want, then I think you are kidding yourselves."

Australian Conservation Foundation national biodiversity policy advisor Brendan Sydes said the frustration and disappointment of conservation groups should be understandable.

"We have had promise after promise after promise, or indication after indication, that there's urgent need for these reforms, and yet here we are, being told that it needs to be delayed or it's not happening now or in one chunk like was originally promised," he told the committee on Wednesday.

Tuesday's announcements were the second stage of the government's Nature Positive Plan.

It initially promised to implement the plan in full by the end of 2023, but it has been split into tranches with significant reform of the nation's main environment legislation delayed into 2024.

Chair of the inquiry, Greens senator Sarah Hanson-Young, believes the government has broken a promise by delaying the environmental law reform aspect to the package.

Australian Associated Press