With underpayment of casual workers in various sectors already a political issue, the coronavirus pandemic has thrown a spotlight on the stand-down clauses in many employment contracts.

The Community and Public Sector Union said on Wednesday it had secured indefinite paid leave for 8000 public servants employed as casuals by the Australian government, and other unions want such conditions for their members.

The Australian Public Service Commission confirmed this "exceptional measure" was in place "for the duration of the pandemic until advised" by the government.

It said, though, that thousands more labour-hire employees working in federal government departments would not be covered, and that their pay was a matter for the labour-hire company holding the contract with the government.

Although the coronavirus is already wreaking havoc through the travel industry - hitting airlines, travel agents and tourist destinations - the employment impacts on other industries are only now unfolding.

In a rare show of left-right unity, the CFMEU and the Australian Workers Union issued a joint statement yesterday calling on mining companies to pay the wages of any worker, including casuals, forced to self-isolate, and to provide an extra two weeks of special leave to anyone infected with COVID-19.

One of the coal industry's major labour hire providers, Chandler Macleod, said this week that it had not seen a coronavirus impact in the mining sector.

"Casual employees within our hospitality business, for example, have been impacted, but we have been able to refer some of them to our supply and logistics clients that have growing demand for staff in their processing and distribution centres," a Chandler Macleod spokesperson said.

"We have also seen some casual employees finishing within the transport and tourism industries, who we have been able to move across to opportunities within the [federal] government."

The joint union call coincided with the federal government's latest Resources and Energy Quarterly report, which predicts modest growth in prices and volumes both for thermal coal for power stations and coking coal for steelmaking.

Resources Minister Keith Pitt said the report's commodities calculations included the impact of the coronavirus - especially on oil prices as demand for air travel fell away - although the situation was, as the report's authors noted, "rapidly evolving".

The CFMEU/AWU concern was triggered at least partly by confirmation that a supplier to BHP's Daunia open-cut in Queensland had tested positive to COVID-19.

The unions said coronavirus concerns were different in the Hunter because its mines were not run on the fly-in-fly-out (FIFO) and mining camp model like Queensland.

NSW Minerals Council chief executive Stephen Galilee said the state mining sector ended 2019 strongly, with record coal export volumes, and any reduction in prices this year had been offset by a weaker Australian dollar, which increased the returns to Australian operations as coal was sold in US dollars.

"It is too early to tell what the longer term impact of the current global challenge will be," Mr Galilee said.

He said the minerals council was working with member companies, governments and other industry associations on coronavirus questions.

"Mining operations are implementing their own workforce protection measures in accordance with public advice, including enhanced cleaning and sanitation, work from home policies, social distancing in crib rooms and new screening measures for visitors," Mr Galilee said.

The United Workers Union said the $250 million announced in a state stimulus package for extra cleaners for schools and other government properties was "too little too late" given the damage the Coalition had done in concert with the four major labour providers, "driving down wages and cutting hours".

Union spokesperson Georgia Potter Butler said Tighes Hill TAFE was one of the places it was concerned about, saying the 26 or so staff were being paid the minimum award rates after a breakdown in enterprise bargaining negotiations with the contract holder, Broadspectrum.

"And it's not just TAFE, it's every school, every courthouse, every MP's office, every government office building, and at the moment frontline staff say they have had virtually no direction on COVID-19," Ms Potter Butler said.

"Obviously the hard work of cleaners is more important than ever at a time like this."

The Independent Education Union, which covers teachers and suport staff in non-government schools, says it has secured an extra 10 days special COVID-19 leave with some employers, and was "fighting to secure ongoing employment for casuals".