More than 30 per cent of ACT public servants have reported an increase in sick days linked to ballooning workloads, according to a Community and Public Sector Union survey.

Of 500 respondents across the ACT public sector, 40 per cent said their workload had "increased significantly" over the past 18 months, and 31 per cent said the increase was dramatic enough to impact their health.

CPSU regional secretary Vince McDevitt said the Government had been "running down" the local public service in a bid to save money.

"That's resulted in a range of measures which have seen ... people dealing with workloads that are ever increasing," he said.

"We've got hundreds of members indicating they're having real problems dealing with workload, to the extent that it's causing stress at home with the family.

"Coming and going in the dark, and you're stressed out all the time — it's just not sustainable."

More than 30 per cent of respondents to the survey also said time pressures at work caused them to skip meal breaks, and 21 per cent said their workload was "very difficult" to complete inside normal working hours.

A majority also said their workplace had undergone a restructure in the past 18 months, with increased workloads a common result.

Mr McDevitt said the increases were not sustainable, and warned that it could impact on productivity in the long run.

"Certainly the ACT Government has reaped millions and millions of dollars in savings through running down the capacity of the local service through these efficiency reviews and restructures," he said.

"But in relation to the service's capacity to deliver quality outcomes for the Canberra community, to do their job properly, to have a healthy and safe workplace, then absolutely, we're in a bad space."