Fianna Fail's Eamon O Cuiv has indicated the party would not be prepared to compromise on the issue of water charges in any negotiations with Fine Gael on the formation of a new government.
Mr O Cuiv was responding after it was revealed that Fine Gael would be willing to drop its plan to abolish the Universal Social Charge if Fianna Fail rowed back on its demand that water charges were suspended.
"You can't have a government which you think is not going to follow the policies which you believe are correct," he said.
"We have given a huge number of commitments, of which the water charge is one," said the Galway West TD.
"People seem to think that the only difference between Fianna Fail and Fine Gael is some minor difference on USC and water charges.
"We have a totally different approach to how this country should go forward."
Asked on Newstalk Lunchtime whether Enda Kenny or Micheal Martin would have the support to become Taoiseach when the Dail sits again on April 6, Mr O Cuiv said: "I can't tell you that.
"There are negotiations going on. There are so many combinations and permutations in the Dail at the moment."
Acting Foreign Affairs Minister Charlie Flanagan said yesterday that while there are various combinations in the Dail "it seems to me a Fine Gael-led government is the most likely outcome".
"There's a duty on Fianna Fail and a duty on smaller parties to play their part.
"I don't believe ultimately there will be a national government, but I believe it's important or incumbent on the larger party groups to play a leading role in forming the next government, because there needs to be a programme for government."