Centrelink has confirmed reports of harsh treatment being handed to former public servants.

About 35,000 public sector pensioners have had their pensions reduced or cut off entirely this year.

The cuts have pushed many below the poverty line, after changes in policy adjusted the terms of their pensions.

Welfare advocates say the goalposts have been moved, leaving former workers unable to have a say about their changing circumstances.

The Federal Government recently began including most public sector “defined benefits” superannuation payments in the income test.

The new rules mean that the level of income from state or federal super schemes that is exempted from Centrelink's income test has been reduced - dropping from 50 per cent to 10 per cent.

The authorities say the move was designed to make sure retirees are treated the same as former private sector workers.

But for tens of thousands of former teachers, nurses, police officers and firefighters as well as state and Commonwealth clerical workers, it means access to the age pension has either been drastically reduced or cut off completely.

“34,820 letters were ... issued to customers in mid-December, notifying of a new payment rate or cancellation of their payment from 1 January 2016, as a result of changes to their income and assets,” a Department of Human Services spokesperson told reporters this week.

The Australian Council of Public Sector Retiree Organisations is outraged at the changed policy, saying it is a slap in the face to retirees who contributed to their super across their working lives.

“The policy seems to have been based on either a misconception or prejudice,” the council's national president Richard Griffiths told the Canberra Times.

The lobby is urging pensioners to voice their displeasure in the direction of their local federal politicians.

Sydney's Welfare Rights Centre says the new government policy will promote consistency between the public and private sectors, but it argues that the changes should have been ‘grandfathered’ so that they would only apply to new retirees.

“The thousands of retirees who will be negatively impacted are not in a position to change their circumstances,” the centre's director Aaron Neal told Fairfax.

“They made retirement decisions based on the rules currently in place and are unable to reverse those decisions.

“Many of these people aren't wealthy retirees, and the average annual income drawn from defined benefit schemes is only $27,550.

“Couples impacted are often living on modest incomes, so there will need to be some belt-tightening all around.

“Pensioners and superannuants contacting our Centre are upset that the Government failed to introduce grandfathering provisions.

“Grandfathering would have avoided the financial harm that people are experiencing as a result of these changes.”