The survey showed Australia's front-line security services are also being affected by the cutbacks, with quarantine inspections as well as the tracking of terrorism, organised crime and illegal immigration all suffering as a result.

Over the past two weeks more than 5000 public servants responded to the survey, which was circulated online by the Community and Public Service Union (CPSU).

It showed recent public service cuts had damaged the service's ability to cater to customers, with 50 per cent of respondents saying they had seen a noticeable increase in customer waiting times.

Additionally, 46 per cent said there had been an increase in customer frustration and aggression.

Public servants in the Department of Human Services said they were the worst hit, with 80 per cent reporting increased wait times and 78 per cent saying they had seen increased customer aggression.

Overall, almost three-quarters of all respondents said they had seen cuts in their department and more than half said there had been a reduction in quality and more mistakes as a result.

CPSU national secretary Nadine Flood said workers were saying they were genuinely worried about the risk of more cuts, which in some cases were undermining Australia's safety.

"If you take the example of quarantine inspection, quarantine staff are telling us they have less boots on the ground, doing checks for pests that can cause billions of dollars in damage to Australian health and agriculture," Ms Flood said.

"That just does not make sense for the government."

Ms Flood said this survey showed the public service was under enormous pressure even before any additional cuts were added in next week's budget.

She said public servants were deeply committed to their work and wanted to do it well, but repeated cuts by multiple governments had put them in a tenuous position.

"This shows the real picture of the impact of cutting more than 6000 jobs since September," she said.