Fianna Fáil says it will consider its support for Fine Gael "one budget at a time".
And the party's leader Micheal Martin says he still doesn't believe the country will be able to afford scrapping the Universal Social Charge.
Earlier the finance minister Michael Noonan told TDs he still believed the charge could be phased out over five years.
But asked if Fianna Fáil would veto the plan, Micheal Martin said it would consider the plans put in front of it.
Our political correspondent Gavan Reilly reports: