Sinn Féin has dismissed the Taoiseach's stance that he will not contemplate coalition with the party after the next election.
Martin McGuinness said yesterday he believed Bertie Ahern may have tried to steal the headlines from Fine Gael after its national conference at the weekend.
He forecast Sinn Féin would make gains in the next Dáil election, and said Mr Ahern may have to do business with his party to form a government.
On Sunday the Taoiseach ruled out making arrangements with Sinn Féin to allow Fianna Fáil back into government after the next election on the grounds that Sinn Féin policies would damage the economy.
Yesterday Mr Ahern said a Fianna Fáil-Sinn Féin coalition would be impossible because the monetary policies of the two were "fundamentally different".
He suggested that Sinn Féin's fiscal, economic, and European policies were "totally at variance with everything I've spent my entire political life doing".
Speaking at Hillsborough, Mr McGuinness said: "In the aftermath of the next general election in the South, Sinn Féin's representation will be quite significantly increased in Dáil Éireann.
"Then all the parties will have to decide what to do vis-à-vis the formation of a government."
He asked rhetorically: "Will we be players in that? I think given the way things are moving forward it's looking very likely that we're going to be. Will Bertie talk to us in that context? Absolutely."
Earlier, the Minister for Foreign Affairs stood by his leader's comments. Dermot Ahern said: "The Taoiseach has made it clear from day one in relation to Sinn Féin moving into the political process exclusively from a democratic point of view in principle.
"The Taoiseach has made it quite clear time and time again that when it comes down to hardball economics and social policy right across the spectrum in the Republic, Sinn Féin are on a different side of the spectrum to my party.
"Themselves and the Labour Party are the only ones to have said they are going to increase corporation and capital gains tax. This is antithesis to the process that my party set out in the Republic in the past number of years.
"[Their stance on] Europe is completely opposite to my party's. Again, Sinn Féin in their recent election manifesto in relation to private property; the ownership of private property being against society.
"I mean there is no way we could ever go into coalition with a party that would say that."
Asked for his response to unionist accusations of Government double standards over its call for coalition at Stormont including Sinn Féin, Mr Ahern explained: "You are dealing with two political landscapes, North and South.
"The political landscape [in the Republic] has been a stable democratic society for decades, and a recent report by Forfás has said that one of the reasons why we have a stable society in the Republic is because we have had stable and accessible government. In relation to the North it's a completely different scenario."
Northern Secretary Peter Hain said he "agreed completely" with Mr Ahern's assessment.
"What we have here north of the Border is constitutional power-sharing. Nobody is seriously suggesting that power-sharing shouldn't be part of the future self-government of Northern Ireland. What happens south of the Border is voluntary power-sharing by parties that choose to exercise it. I think it's good that real politics and policies are bursting out from underneath the constitutional disagreements that have dominated this island of Ireland for so long."