The Government would find it very hard to change pension agreements for public sector workers, according to a leading economist.
Minister for Public Expenditure & Reform Paschal Donohoe wants the Public Service Pay Commission to take pensions into account when discussing future wage agreements.
Existing pension arrangements cost the state €3.3bn a year.
Public sector unions have said there will be no concessions on pensions - and economist Colm McCarthy says it would be hard to enforce.
"That €3.3bn all goes to people who are already retired, and who have been promised this amount of money," he said.
"It's very difficult to see how the Government could come along - it's never been done - and say: 'I'm sorry mate, even though you're 76 and a half, and you're not going to work again, we're going to cut your monthly pension'."