Queensland’s Palaszczuk government has granted the final major approval for the controversial Carmichael coal project in Central Queensland.

But the green light has increased pressure on Indian energy giant Adani to show how it will fund the $16.5 billion mine.

It also means environmental activists have a new legal avenue to challenge the decision to grant the mining lease.

Adani is talking big about its continued commitment to the mine, rail and port project, saying construction is set to begin in 2017.

The company has slammed what it calls “politically motivated” activists that have hampered almost every step of the project for the past five years.

Proponents including Adani and the Queensland government still claim the project will create 9500 jobs, despite admissions in court suggesting that number might be much lower.

Chief economist at the Australia Institute, Dr Richard Denniss, says even casual analysis of the project suggests the mine will not be viable.

"It's hard to understand why, rather than go and buy cheap distressed coal mines for sale across the world, they want to spend $16 billion on building a new one," he told the ABC.

"Whether it's integrated or not, it makes no sense to go the most expensive option imaginable."

“It is important to note that successive legal challenges to science-based approvals, which are the strictest of their kind for a major resources project in this country, are designed to deny the job creating benefits of the company's mine, rail and port projects to our state,” Adani said in a statement on Sunday.

“It is for this reason that conclusion of second tier approvals and resolution of politically motivated challenges is the company's principal focus, prior to final investment decision being made.”

Adani Australia chief executive Jeyakumar Janakaraj says pre-engineering work that was suspended in 2015 is about to restart, while workers are being hired to start construction as well.

He said Adani was already looking at more mines to open in the Galilee Basin.

The Carmichael project has been held up as a key target in the fossil fuel divestment movement.

Legal challenges by environmental and Indigenous groups could continue to make some banks wary of lending money to the project.

Among the legal criticisms is a challenge by an Indigenous group representing the Wangan and Jagalingou people, which questions the native title determination of the land.

Meanwhile, the Australian Conservation Foundation is challenging federal Environment Minister Greg Hunt's approvals for the mine as well.

Adani’s project has also been tainted by claims of corruption and environmental damage from its business activities in India.

Carmichael marks the first mining lease approval in the frontier Galilee Basin, where other big players like Gina Rinehart's Hancock Coal and Clive Palmer's Waratah Coal have struggled to get projects off the ground.

Mr Palmer says Adani will struggle to get the numbers to work.

“On the current coal prices these projects are not commercially viable and no banks will support it,” Mr Palmer told Fairfax reporters.


“On project finance you need to show a return to get the money back. It doesn't matter they can take the coal and use it themselves. It's cheaper at the moment to buy it from somewhere else.”

Queensland Premier Annastacia Palaszczuk says it is still up to Adani to make the final decision on whether to proceed.

“This is a major step forward for this project after extensive government and community scrutiny,” she said.

“Some approvals are still required before construction can start, and ultimately committing to the project will be a decision for Adani.”

The mine's environmental approval includes about 140 conditions designed to protect local flora and fauna, groundwater and surface water resources, as well as controls on dust and noise.

There are also 99 conditions on the rail and port elements of the project, and Adani has been blocked from starting dredging at the Abbot Point coal terminal in north Queensland until it reaches financial closure.