Minister for Agriculture Simon Coveney has said Michael Noonan would be very foolish to rule out any option ahead of a full budget discussion.
He was commenting on Opposition claims that the Minister for Finance was preparing the ground for a U-turn by refusing to rule out tax increases.
Speaking at Farmleigh, Mr Coveney said the country faced huge challenges and the Government needed to keep an open mind.
Yesterday, the Minister for Finance said he was not going to rule out any tax initiative, or any tax increase, or any tax reduction, in the light of the state of the country's finances.
Michael Noonan told the Dáil that he was saying this at a level of principle, and that he had nothing in mind.
Asked by Fianna Fáil's Michael McGrath if this included income tax, Mr Noonan declined to specifically rule out changes to income tax, but referred the deputy to the Programme for Government, saying this gave the 'principles' on which the Government would base its tax approach.
The programme commits the Government to maintaining the current rates of income tax together with bands and credits, and not to increase the top marginal rates of taxes on income.