An ex-soldier has sounded the alarm on the "wicked problem" of more veterans waiting longer for help because of a growing reliance on contractors to process claims.
Defence Force Welfare Association national president Kel Ryan, who served in Vietnam, also says some call centre staff used by veterans' affairs are abrupt and lack empathy.
"There's a lack of empathy with regards to some call centre staff ... who are dealing with veterans who cover the spectrum from WWII through to yesterday," Mr Ryan told a federal parliamentary committee on Tuesday.
He said the Department of Veterans' Affairs faced a "wicked problem" as a growing number of veterans came forward for assistance and the department relied increasingly on labour hire because of staffing caps.
The processing of compensation and other claims would only improve if there was a well-trained and stable public sector workforce, Mr Ryan told the Senate committee.
The Community and Public Sector Union said the increasing demand for help combined with a squeeze on resources created a perfect storm that was disastrous for veterans.
The department was dealing with 323,000 veteran "clients" and each staff member was expected to manage at least 130 claims, CPSU national secretary Melissa Donnelly said.
She said more than 4300 liability claims over a year old were yet to be processed, while almost 50,000 overall claims remained unprocessed at the end of 2020.
Labour hire staff often left because of the lack of job security and it ended up being more expensive for the department, Ms Donnelly said.
"What (labour hire staff) have told me often is that they really believe in the work, they're committed to the work, they would like to stay there but they cannot without the kind of job security that a permanent job would entail," she said.
Departmental officials told the committee the staffing cap had been increased in the 2021/22 federal budget.
This meant the department could somewhat reduce its reliance on labour hire and increase the number of permanent staff.
But the department said it would need to continue to rely on a mix of labour hire companies and public service employees.
Chief operating officer Mark Harrigan acknowledged the significant workload.
"Our way to address that, to get through the claims to a high standard, is to bring the bodies on that we need, the individuals that we need that we can accredit to get the work done," he said.
"Whether they be taking phone calls from veterans, whether they be processing claims from veterans, our focus is on addressing the workloads, getting through the backlogs and this has necessitated a need to supplement our APS (public service) workforce with a non-APS workforce."