The Government last night insisted that it would not recall the Dáil in advance of any attack by the US and Britain on Iraq.
With hostilities increasingly likely after the US set today as the deadline for agreement on a new UN resolution, the Opposition insisted that the Dáil should be recalled immediately.
However, a Government spokeswoman said there were no such plans, adding that the Cabinet meeting scheduled for Wednesday had not been brought forward.
The Government was waiting to assess the outcome of today's UN Security Council meeting, she said.
The Taoiseach, Mr Ahern, has already given an indication that the Government may allow the US military to use Shannon Airport even if it attacked Iraq without the support of the UN Security Council.
However, the Cabinet is expected to meet to finalise its position before any debate in the Dáil.
With the Dáil not scheduled to sit again until tomorrow week, an emergency meeting of the Cabinet before then is likely to be held if war begins.
Fine Gael, Labour and the Greens all said the Dáil should be recalled before any hostilities.
The Fine Gael leader, Mr Enda Kenny, said there was no reason for the Dáil to remain in recess.
"In the event of the US invading Iraq without the consent of the UN, the Government would have to tell the US that we're closing off Shannon," he said.
This stance was echoed by the Labour leader, Mr Pat Rabbitte, who said the Government was exaggerating the potential economic impact of a decision made in accordance with neutrality and international law.
The Green foreign affairs spokesman, Mr John Gormley, said the Government faced an "overwhelming" backlash if it did not withdraw permission to use Shannon.