A peak union is concerned about the workload of state public servants who stay in their jobs, after a large number accept voluntary redundancies as part of Government measures to trim the Budget.

The Community and Public Sector Union secretary Toni Walkington says she is not surprised that 1,100 bureaucrats have applied for voluntary redundancies, but she is worried what it will mean for those who remain.

Ms Walkington says there will be obvious gaps in service delivery with fewer people required to do more, particularly as the State continues to experience significant population growth.

She says it is the public who will suffer the consequences.

"What's clear is that the Government expects people to take on the workload, but our members are saying to us that it's just not possible," she said.

"They're already working quite excessive hours, often unpaid, so it's not registering as a cost to the Government."

In a statement, the Treasurer Troy Buswell says the voluntary redundancy program is targeted, with the emphasis on encouraging "surplus or underemployed staff" to go.

He says the expectation is that it will not impact on the delivery of frontline services.