Shannon Airport has been used in previous conflicts where there was no UN resolution in place, the Taoiseach said during a stormy Dáil session.
Repeatedly pressed by an irate Opposition about Iraq and the adjournment of the Dáil for 13 days without debate, Mr Ahern refused to say what the Government's position would be in the event of no UN resolution being agreed on Iraq. He had not said it since September, he pointed out, and "will not do it now".
Mr Ahern also criticised the French government. "At least I have a consistent position and I am not like the French, who allow the US to overfly, despite the fact that they are against the war and may veto a new resolution," he said.
He told the Dáil that on a "strictly legal interpretation" of advice he received, the issue of overflights and landing at Shannon did not arise because of precedent. Shannon had been used during the Vietnam war and more recently in Kosovo, he said.
"There are many examples over the years of where there were no resolutions but Shannon was available", he said. "Therefore, it is not an issue on a legal basis but there is more to this than law."
The Opposition however interpreted this as giving the go-ahead for the military use of Shannon Airport. "The Taoiseach as good as said this morning that irrespective of legality or otherwise, he will allow Shannon to be used for military purposes," said Mr Michael D. Higgins, Labour's foreign affairs spokesman.
He condemned the Government for refusing to have a debate on Iraq, and accused the Taoiseach of "fudging" the issue of his view on the illegality or otherwise of a pre-emptive strike.
In an impassioned speech, he said it was a disgrace that a conflict that could result in 100,000 direct casualties, with up to 15 million people on food aid, did not merit a debate.
Mr Higgins added that the "blood of Iraqi children and civilians" would be on the hands of the Government side who would not permit a debate.
The Dáil "will have been shamed" he declared to a round of applause from the Opposition, adding that the Taoiseach was "slinking off" to the United States.
Angry exchanges continued from the start of the Dáil and questions from Opposition leaders, to the Taoiseach's Question Time and into the Order of Business.
The Fine Gael leader, Mr Enda Kenny, first raised the issued during Opposition leaders' questions and asked the Taoiseach to outline what he would be saying to President Bush during their half-hour White House meeting today and what his position was. Mr Ahern said that "in the absence of a second resolution, we will set out a position in a way that befits whatever action we must take".
Asked what that meant, the Taoiseach said: "There is no point in asking for the recall of the House in order for the Government to restate its position when the situation arises, while at the same time calling on me to state that position now. I have not stated it since September and I will not state that position now."
When Mr Ahern said that even France was going to allow overflight facilities, Mr John Gormley (GP, Dublin South-East) said France was not neutral but was a member of NATO. Pressed again about the Government's position, Mr Ahern said "our position is consistently and strongly one of support for the work of the United Nations until such time as that fails".
The Green Party leader, Mr Trevor Sargent, said the Taoiseach should clarify which UN he stood by, whether it was the US or the French view, but the Taoiseach replied that there was one UN and Ireland was a "faithful servant" of the UN.
