As the Taoiseach travels to Brussels to attend the emergency European Union summit on Iraq today he faces increasing opposition at home to military action and to the Government's stance on the issue.
Up to a 100,000 people attended a mass anti-war demonstration in Dublin on Saturday that heard calls for the Mr Ahern and his Coalition colleagues to oppose a war on Iraq and to ban the US military from using facilities at Shannon airport.
The Fine Gael leader, Mr Enda Kenny, repeated his call this morning for the Government to rule out Irish support for any unilateral attack on Iraq by the United States.
"Last week in the Dáil, I asked the Taoiseach to state unequivocally where he stood on this fundamental issue, but he refused to answer," Mr Kenny said.
"The demonstrations in Ireland and around the world have again shown that there is huge public opposition to any unilateral strike against Iraq".
Mr Richard Boyd Barrett, chairperson of the Irish Anti-War Movement, and one of the chief organisers of Saturday's protest said: "On Saturday the people of this country stood up and said no to war and the use of Shannon by the US military.
"Rather than listen to what people are saying the Government are trying to twist things and put their ownspin on the march. Incredibly one government Minister has said the march was not incompatible with government policy. This is dishonest rubbish.
"The clear message that came from the march was that people oppose war on Iraq with or without UN sanction and that they oppose the use of Shannon by the US military," Mr Boyd-Barrett added.
The Green Party chairman, Mr John Gormley, said this morning that he hoped the Government would take notice of the protest. He called on the Government to stop "fudging" the issue of its military neutrality and said it had a "moral duty" to oppose any war.
"Fianna Fáil prides itself on having its finger on the pulse - its founding father De Valera said he only had to look into his own heart to know what the Irish people thought," said Mr Gormley. "So I hope they will listen to the Irish people".
"I think it is time that we as a so-called neutral country made our position clear, in line with other neutral countries in Europe, because we are out of sync with them," he said on RTÉ radio.
"I want the Government to come out very clearly and say it is opposed to the war and stop facilitating the American war effort".
Mr Tom Kitt, Minister of State for Foreign Affairs, said: "I'm very happy with the protest on Saturday. In fact it is very much in line with my own view and with the Government's view".
He added: "It is important in any situation that the Irish Government and politicians get a feel for what the public are thinking. I always predicted a very big march on Saturday".
After Saturday's march Labour leader Mr Pat Rabbitte said the Government had greatly misjudged the depth of anti-war feeling in the Republic. He said it proved public opinion had been vastly underestimated.
