People with disabilities left the workforce four times faster than they were hired in the past year leading concerned disability advocates to call for reforms to federal government hiring procedures.
In the past year, 535 people with disabilities left the public service, 46.4 per cent of whom were retrenched, compared with only 119 engagements in the same group.
Public service workers with a disability were more likely to be made redundant than their coworkers and half as likely to leave of their own accord.
A spokeswoman for Public Service minister Eric Abetz said the numbers were due to the hiring restrictions and were broadly proportional to the number of employees leaving.
Due to a 0.2 per cent increase in public servants disclosing a disability, the number of people with a disability has increased to 4778, still the second lowest number in 11 years.
In the rest of the public service, there were 11131 separations in 2013-14 compared with 4672 new public servants taken on board.
Only 19.1 per cent of people with disabilities resigned from their positions in the past year, compared with 36.2 per cent of the general workforce.
ADACAS chief executive officer Fiona May said given the federal government's new restrictions on the disability support pension it should be working hard to be model employer of people with disabilities.
"It makes it hard for them to stand tall and encourage other employers and sectors to employ people with disabilities," she said.
"There's plenty of evidence that people with disabilities make great employees so if the federal government is convinced that people with disabilities need to be in work rather than on the pension, then they need to lead the way in employing [them]."
Advocacy for Inclusion general manager Christina Ryan said while it was great to see an increase in numbers, losing such a large proportion of people with a disability meant they were going backwards.
"To me, that's an indication of some cultural reform being needed ... the public service will have to change the way it operates if it's serious about keeping people with a disability in its workforce," she said.
Ms Ryan said the entry conditions into the public service were not conducive to people getting off benefits.
A spokeswoman for Mr Abetz said there was an under-reporting of the number of public service employees with a disability, due to employees being given the choice of whether or not to disclose this information.
She said when there were hiring restrictions in place, there would always be many more people leaving than joining the service.
"The government is strongly supportive of employing people with disabilities, via the APS Disability Employment Strategy and initiatives such as the recently established APS Disability Champions Network," she said.