The public sector union is calling on the federal government to suspend its controversial Centrelink debt recovery system, warning the public will suffer as staff struggle to cope.
The CPSU says service standards have already dropped to unacceptable levels following thousands of job cuts in the Department of Human Services, with the latest scandal piling on more pressure.
The Commonwealth Ombudsman is investigating the system, which the government is using to claw back $4 billion in overpayments to welfare recipients.
"This scheme is an absolute nightmare for thousands of Centrelink customers who've done absolutely nothing wrong, and the staff who are bearing the brunt of this mess," Mr Tull said.
He said staff have been struggling in a system that's been in crisis for years, with the union concerned about Centrelink's ability to cope in coming months.
"The serious problems with this debt recovery program are piling on even more pressure, and feeding more aggression from understandably frustrated customers.
"Thousands of jobs have been cut in the Department of Human Services and that's why service standards have dropped to unacceptable levels, including 36 million missed calls to DHS just last year alone.
"This is an agency in desperate need of proper resourcing, otherwise it's the general public who will continue to suffer."