Environment Minister Melissa Price is still working on sub-approvals for the controversial Adani coal mine, despite a threat from a Liberal senator to call for her resignation.

Treasurer Josh Frydenberg, who was environment minister before Ms Price, said the vast majority of federal environmental approvals were done.

But Liberal senator James McGrath, who famously helped bring down Tony Abbott and Malcolm Turnbull, has now turned his attention to Ms Price.

He reportedly will publicly call on her to resign unless she urgently approves the groundwater management plan for the central Queensland mine before the government goes into pre-election caretaker mode.

But Mr Frydenberg played down the tensions when asked about the threat on Monday.

“Melissa Price is going through the proper process, working with the scientists, taking the best possible advice,” Mr Frydenberg told reporters in Melbourne.

“The Adani project is one where the major approvals have been given and it is now going through the sub-approvals.”

Mr Frydenberg said there were “180 rigorous environmental conditions attached” to the Adani coal mine project.

Finance Minister Mathias Cormann said Senator McGrath’s public intervention wasn’t helpful.

“I would have much rather if he had not made that sort of communication but he has and we are where we are,” he told a Senate hearing.

Anti-Adani protesters disrupted a business lunch speech by Prime Minister Scott Morrison in Brisbane on Monday.

“I’ll come to climate, don’t worry about that mate,” Mr Morrison said after one of the disruptions.

“Our government inherited a climate deficit from the Labor party when we came to office.”

Mr Morrison said the final approvals were “quite minor matters”.

“Like in all the other cases, we will be relying on the scientific evidence that is provided to the government in making those decisions,” he told reporters.

Labor leader Bill Shorten said the environment minister was being bullied.

“LNP politicians are bullying the minister for the environment – saying ‘You will lose your job if you don’t give us the answer we want on Adani’,” Mr Shorten told reporters in Brisbane.

“This is a failure of ethics in government at the highest level.”

Mr Shorten said in government he would be guided by the “best science and the law of the land” on the Adani approvals, but no taxpayer money would go to the project.

Queensland Nationals and conservative Liberal MPs are increasingly restless for the Galilee Basin project to go ahead, but their colleagues worry it will hurt the Victorian vote.

Adani has said it will self-fund construction of a scaled-down version of the original mine plan.

A Senate estimates hearing was told Ms Price was briefed on the groundwater management plan by departmental officials last week.

The briefing included detailed work by scientific agencies CSIRO and Geoscience Australia.

Government minister Simon Birmingham said all relevant reports would be provided to the Queensland government and be made public.