Adani's Australian boss says he is scratching his head over an "11th-hour" decision by the Queensland Government to reject its management plan for an endangered finch, further delaying its multi-billion-dollar project.

Key points: The largest known population of the endangered black-throated finch, southern subspecies, is on the mine's site

The largest known population of the endangered black-throated finch, southern subspecies, is on the mine's site Queensland Government wants more information on population and available seed before the management plan is approved

Queensland Government wants more information on population and available seed before the management plan is approved Adani says it is ready to begin work on the mine, but approval processes are hindering progress

The Indian miner met with the state's Environment Department on Thursday where it was told a number of new commitments need to be met before the plan is approved.

Adani Australia chief executive Lucas Dow said the Government was trying to stall, but the company would work "feverishly" to meet the new demands.

"We're not going to be pig-headed about it," he said.

"If there are areas there that we need to make changes to the plan, we will clearly do that.

"Department officials that are presiding over this have been reviewing those plans throughout 18 months, so to now get to the 11th hour and have them provide some additional requirements they believe are required have left us scratching our heads a little.

"The Queensland Government has dragged their feet to this point."

The black-throated finch population at the site represents the largest known population of the endangered southern species, a department spokesperson said.

Adani's management plan had been approved by the Federal Government, and was one of two approvals that need to be cleared by the State Government before work could begin on constructing the mine in the Galilee Basin, in central Queensland.

The new demands come after an independent report was ordered by the Government.

Adani Australia CEO Lucas Dow said the company will comply with the new requirements. ( ABC News: Chris Gillett )

The commitments sought include: gathering more information on the population, committing to a limited grazing regime in the project area, and providing sufficient detail of research that will determine availability of seed throughout the year.

"The department … has advised Adani that it cannot approve its black-throated finch management plan in its current form because it does not meet the requirements of the company's environmental authority", a spokesperson said in a statement.

"This position is based on the best available science."

Adani can now submit a new or revised management plan for the bird.

'Queensland Government caving to the Greens'

Adani has mining and environmental licences from the Queensland Government but it still needs the state to sign off on two environmental plans — one for the black-throated finch and one for groundwater.

Adani managed to get federal approval for its groundwater plan on the eve of the Morrison Government hitting caretaker mode in the election campaign.

Adani's Carmichael coal mine site in central Queensland's Galilee Basin, taken last year. ( Twitter: Matthew Canavan )

Federal Resources Minister Matt Canavan said the State Government's decision was a classic example of the Labor Party siding with the Greens.

"We've seen Bob Brown and his convoy come up here this week, we've seen the Labor Party do a preference deal with the Greens and surprise, surprise, the Labor Party once again caved in to the demands of the Greens and the likes of Bob Brown," he said.

"It's the same management plan that's been approved by the regulators and scientists at a Federal Government level.

Bob Brown's Stop Adani convoy travelled through major cities in April, rallying against the proposed mine. ( ABC News: Tim Swanston )

"The reason they're singling out this mine is because the Greens have asked them to do it."

Stop Adani Townsville spokeswoman Wendy Tubman said she was not surprised it failed to meet the environmental requirements.

"We're talking about an endangered species, we're talking at a time where we are facing its mass extinction worldwide and we have to take protection of our endangered species very seriously," she said.