Ireland and each EU member state will now only keep a commissioner "if Lisbon enters into force", Taoiseach Brian Cowen has insisted during a Dáil debate on last week's meeting of European leaders.
There were sharp exchanges between Mr Cowen and Sinn Fein Dáil leader Caoimhghín Ó Caoláin about the agreement reached in Brussels and the retention of a commissioner. Sinn Féin was the only party in the House to oppose the Lisbon Treaty in the referendum in June.
Fine Gael foreign affairs spokesman Billy Timmins hit out at chairman of the Road Safety Authority Gay Byrne for remarks he made on the referendum.
"If Mr Byrne and other commentators intend to participate in a national debate, they should at least afford the public the courtesy of learning the issues before they pass pronouncement.
"Their views will be respected even by those who disagree with their judgment if they are based on informed knowledge," he said.
Mr Cowen told the House that "only if Lisbon enters into force will Ireland, and each member state, now keep a commissioner".
He insisted that "maintaining one commissioner per member state is not possible under the existing treaty arrangements. The Nice Treaty requires the size of the commission to be reduced."
Mr Ó Caoláin accused the Government of arrogance and claimed "they attempt to confuse a number of issues in order to give full rein to fear and misinformation in a rerun of the referendum".
But Mr Cowen interrupted: "Your party's canvassers were going around my town talking about conscription."
Earlier Mr Ó Caoláin said "critically and clearly, no changes to the Lisbon Treaty as presented to the Irish electorate, either by amendments to the text or by protocols, have been secured".
Mr Cowen insisted "the conclusions state they are legally binding guarantees".
Mr Ó Caoláin said the Taoiseach "does not have a clear vision, in written form or otherwise, of what was allegedly agreed in the run-up to and during the European Council meeting which took place last week".
But Mr Cowen said that "one advances the position nationally in so far as is possible, based on the ability of others to agree with one".
He added that "the treaty can only be agreed, not on the basis of a diktat of his party or mine, but on the basis of a consensus agreed among 27 member states."
Mr Timmins referred to comments by Gay Byrne during the referendum campaign when he said he agreed that "the entire thing is unintelligible bilge". Deputy Timmins said "if I adopted the same approach to the transport legislation on road safety as Mr Byrne has done on this occasion, I would be saying to the public that if they had a vote on this legislation, do not pass it because they will not understand it. That approach is too simplistic.
"It is too serious a matter for opinion makers to adopt that approach. One goes out and informs oneself of the rights or wrongs."
Labour leader Eamon Gilmore said "this is by no means a done deal". He welcomed "the recognition in Europe that the same question cannot be put to the people again. Significant changes are required . . ."
