The NSW Government has ordered its departments to find $1.6 billion in savings over the next four years.

The state has lifted the annual efficiency dividend for government agencies from 2 per cent to 3 per cent.

NSW Premier Gladys Berejiklian has been called to defend the cuts to the public service, but she says frontline staffing is rising to levels unmatched by other states.

“Our strong budget position has meant we have literally employed thousands and thousands of extra frontline public servants where our communities need them,” Ms Berejiklian said.

“No other governments have employed as many frontline workers as we have in [this] short amount of time.”

Unions NSW secretary Mark Morey expects staff cuts.

“I'm sure there will be some savings in departments through technology [advancements],” he told Fairfax.

“But the vast bulk of it will actually be job cuts.”

The NSW Teachers' Federation is concerned hundreds of support staff at public schools will have to go.

“The loss of these positions will mean that principals and teachers will be forced to pick up this administrative work. This will take away time from teaching and learning,” Henry Rajendra, the union's senior vice-president, told reporters.

NSW Treasurer Dominic Perrottet said the government wants “less middle managers in the public service, more teachers, more nurses, and more coppers”.

“In yesterday’s budget we had expenses of $76.5 billion. We want our public servants working for the people of NSW. If government can’t find 3 per cent in savings, I think that is a problem,” he said.

“And if you look in the budget, [there were] record amounts of investment in frontline public servants: 950 new nurses and midwives, over 800 new teachers, 100 new police,” he said.

Public Service Association secretary Stewart Little said the budget cuts would allow the public sector to better service the demands of a growing population.

“Each year the Berejiklian government will be growing the state’s population by 1.6 per cent and cutting public services by 3 per cent,” Mr Little said.

“In the end it will be the people of NSW that suffer. The government waves shiny high-profile initiatives around like they’re Santa, while at the same time viciously eroding the foundations of public services.”