On budget eve, the Liberal-Nationals opposition made a last-ditch demand to the Labor government to scrap the levy recommended by the mental health royal commission to fund rebuilding the broken system.

"Mental health is core business of a state government," Opposition Leader Michael O'Brien told reporters on Wednesday.

"Mental health should be funded from general revenue, not from a special tax."

Mr O'Brien said adding financial distress to households could potentially trigger poor mental health and the state's economy needed to grow after the long 2020 coronavirus lockdown, not be taxed further.

In general, the government should look to cutting waste from across government, he said.

But Health Minister Martin Foley stuck by the inquiry's recommendations, which Labor promised to fully implement during the 2018 state election.

"We know that the royal commission into Victoria's mental health system pointed to a broken system, it pointed to a system that is at the moment costing communities and individuals and families huge amounts of trauma for bad responses that in many respects are getting worse," Mr Foley said on Wednesday.

"The royal commission into Victoria's mental health system recommended a dedicated funding stream.

"I'm sure that the treasurer and acting premier and mental health minister will have more to say about mental health as a key pillar of tomorrow's budget."

While the opposition has encouraged the state to take a knife to bureaucratic spending, the Victorian Greens are urging the government not to make further public sector cuts.

Last week, Treasurer Tim Pallas confirmed the guaranteed annual increase of taxpayer-funded jobs will be cut from 3 per cent to 2 per cent from 2022.

Teachers, nurses, paramedics, firefighters, police officers and the public service are among those affected.

In 2019, the government paid consultants $9 million to conduct a "base review" of the public sector in an attempt to identify potential savings and cuts.

But there were no changes to the sector in 2020 due to the COVID-19 pandemic.

Victoria's top public servant Jeremi Moule on Saturday wrote to his colleagues to tell them changes would be made to help "deliver the government's reform agenda".

Victorian Greens deputy leader Ellen Sandell said any public sector cuts would hurt the economy and is the "opposite of what we should be doing in a pandemic".

The Community and Public Sector Union said the wage cut "seems to be the reward ... for our heroic efforts during 2020 combining to fight bushfires and the COVID-19 pandemic".

Australian Associated Press