The Coalition government's "ideological dislike of public servants" could be behind the cuts to pensions set to hit tens of thousands of retirees within days, according to a leading advocacy group.
Retired police officers, firefighters and nurses, as well as former state and federal public servants, will see their Centrelink payments reduced under new rules, known as the "10 per cent cap" which came into force on January 1.
But the federal government says the changes simply bring the rules for retired public sector pensioners into line with those of other pensioners.
Social Services Minister Christian Porter says the changes, which will not apply to military and Veterans' Affairs pensioners, are all about consistency.
The cap drastically reduces, from 50 per cent to 10 per cent, the proportion of a retiree's payments from their superannuation savings that can be exempted from the Centrelink income test for the age pension.
The Australian Council of Public Sector Retiree Organisations (ACPSRO) says that many will only learn their incomes are to be slashed on the first pension day of the year.
ACPSRO says it is getting calls from pensioners all around Australia whose incomes are being slashed, including a Tasmanian couple, whose only assets are their caravan and car, who have lost $161 a fortnight.
The council's president, Richard Griffiths, said the policy change ignored the original purpose of state super schemes which were fully funded and meant to provide a living income to the states' retired public sector workers.
"Alternatively the budget policy, which has been made in advance of any community-wide reform of national retirement income policy, was based primarily on an ideological dislike of public servants." Mr Griffiths said.
He said the original projection that 47,000 retirees would see their pensions cut through the revised cap now looked like a gross under-estimation with 5500 state superannuants in Tasmania alone who would see their fortnightly payments slashed.
"So the total for all the other states and territories, plus the Commonwealth, plus non-government retirees on schemes like UniSuper and residual corporate defined benefit schemes, seems likely to be much higher, even before affected families are included.
"The public sector retirees who are affected include not only what some might like to think of as just paper-shuffling bureaucrats, but retired teachers, firefighters, nurses and police, people whom almost all of the public would recognise as being useful citizens."
But a spokesman for Mr Porter said the changes were about ending an anomaly that gave an advantage to defined benefits pensioners.
"We simply want people to be treated consistently," the minister's spokesman said.
"This change will enable a fairer assessment of a person's need for income support.
"Under the previous rules for defined benefit income streams, there was an anomaly which resulted in some people having a higher deductible amount, and consequently higher income support payments.
"This meant that they may be receiving more income support than people who had the same amount of income from a different source.
"What we are trying to do is have a system that treats people consistently and equally."