The Irish/British declaration that the Belfast Agreement will not be compromised by an amendment to the Constitution on citizenship is recognised in international law, the Taoiseach, Mr Ahern, told the Dáil today.
While Opposition parties debating the proposed change to Article 9 of the Constitution on the right to citizenship repeated their concerns, Mr Ahern insisted the Interpretive Declaration "copper-fastens" the integrity of the agreement.
The two governments have taken separate legal advice on the issue and by signing the declaration have "eliminated" any possibility of the Agreement being compromised, he said.
"That there is, and will be, no breach of the British Irish Agreement, is now beyond dispute," he added.
Sinn Féin's Mr Caoimhghín Ó Caoláin accused the Government of entering into secret talks with the British when framing the Interpretative Declaration
He said the Minister for Justice, Mr McDowell, who is proposing the amendment, was "unpicking" the Belfast Agreement and disregarding its principles.
Fine Gael leader, Mr Enda Kenny said: "The fact that the Government chose to consult with the British Government while keeping the political parties in Northern Ireland in the dark only served to further fuel suspicion," he said.
And Labour leader Mr Pat Rabbitte, said the Government was "fundamentally dishonest" in claiming the affect on the Belfast Agreement was not anticipated.
Mr Rabbitte referred to a letter written by the Taoiseach in 1998 in which he said "considerations of peace in Northern Ireland would outweigh any concerns relating to immigration."