Party leader Micheál Martin also said that the elderly must be protected in the Budget and has vowed to fight any change to the free travel scheme for pensioners.
It follows comments from Junior Minister Brian Hayes saying that pensioners had escaped the worst of the cuts so far.
Deputy Martin has attacked Deputy Hayes for suggesting that pensioners should be paying more.
He was speaking as his Parliamentary Party gathered for a meeting in North Dublin before the Dáil returns tomorrow.
Mr Martin insisted that only the wealthiest pensioners should be asked to pay up. He said fairness must be returned to the centre of the budget process and that his party will oppose plans for a value-based property tax in December.
A property tax was first suggested when Deputy Martin was a government minister but he says now is the wrong time to bring it in.