Proposed speaking rights for Northern Ireland MPs in the Dáil would be an act of aggression against unionists and jeopardise any future relationship, it was claimed today.
The Democratic Unionist Party said the planned concessions were short-sighted and would represent a quasi-constitutional claim on Northern Ireland, which had frustrated political progress for decades.
The Taoiseach, Minister for Foreign Affairs, Mr Ahern and the Minister for Justice, Mr McDowell speaking to the DUP in Dublin today.
DUP leader the Rev Ian Paisley also called on Secretary of State Peter Hain to resign over reported comments that the current Northern Ireland economy was unsustainable and needed to be put on an all-Ireland footing.
Speaking after a 90-minute meeting with Taoiseach Bertie Ahern in Dublin, Mr Paisley said: "The Irish Government should not jeopardise the prospect for a proper constructive relationship between our two countries.
"Disturbing the present constitutional balance would be a short-sighted step with far-reaching and long-term consequences."
The DUP leader said all parties must work towards building a relationship which is practical rather than politically-motivated.
Mr Paisley also added that he did not believe that the Independent Monitoring Commission would be in a position to give the IRA a clean bill of health in its report due in January.
Mr Paisley said the DUP had held two meetings with the Independent Monitoring Commission (IMC) in recent weeks.
The North Antrim MP said: "The IMC has told us that in no way will they be able to say in January that they can give a clean bill of health to IRA/Sinn Fein."
The DUP delegation also told Mr Ahern the Colombia Three must not be allowed to stay in Ireland and should be swiftly extradited.
"We conveyed in the strongest possible terms that allowing these fugitives of justice to live freely within the Irish Republic is unacceptable," the DUP leader said.
"As far as the DUP is concerned, there can be no fudging of the line between democracy and terror." Ruling out the prospect of power-sharing talks beginning in the New Year, Mr Paisley said the IRA had to go out of business in all its forms for good.
"There can be no toleration of criminality. We cannot have any progress until terrorism from all quarters is dealt with." The North Antrim MP described today's meeting as forthright and businesslike.
The DUP delegation included Ian Paisley Jnr, Nigel Dodds, Peter Robinson and Arlene Foster. Mr Ahern was joined by Minister for Justice Michael McDowell and Minister for Foreign Affairs Dermot Ahern.
Speaking afterwards, Dermot Ahern described the meeting as "very good" and said he understood the caution of the DUP about sharing a devolved government with Sinn Fein.
"They are obviously going to be cautious, but there was nothing in their remarks to us that they were not going to go back into devolved government.
"They're going to take their time and be cautious."
Dermot Ahern also said the Government had cleared up many misconceptions about offering speaking rights in the Dail parliament to Northern Ireland MPs.
He said the MPs would not be members of any all-party committee but would only be invited to speak on relevant issues. "A lot of the misconceptions that they had, I think, were dispelled," he said.
Mr Ahern said that he did not want a political vacuum to be created before the IMC report, due in January. "But, at the same time, we will try to tic-tac with the parties between now and January. "Depending on what the IMC says, we will expect progress to happen thereafter," he said.