The Taoiseach Mr Ahern has said the Government's top-level National Security Committee did not see the use of Shannon by US aircraft as a potential security risk to the country.
has said there will be no change in Government policy allowing US war planes to stop over in Shannon Airport en route to Iraq.
Mr Ahern said that legislation had been in place since the late 1950s permitting approved US military aircraft to overfly or land in Ireland and he saw no reason to change this now.
A World Airlines plane, used for carrying US Troops on their way to Iraq, stops to refuel at Shannon Airport. Photo: Frank Miller
Speaking during Question Time in the Dáil, Mr Ahern said: "There is no change in the situation regarding the Shannon stop-over and I don't think we should talk it up."
But Green Party leader Mr Trevor Sergeant reminded the Dáil of the comments of US civil rights campaigner Rev Jesse Jackson that ongoing use of Shannon by US warplanes placed us "in the line of fire".
He also asked whether some aircraft were being checked for "unspecified cargo which is neither searched for weapons or inspected for compliance with air safety or fire regulations".
Mr Ahern said that Mr Jackson spoke to him before he left the country and he assured him that the comments didn't represent his views and they were being quoted mischievously.
Labour Party leader Mr Pat Rabbitte asked: "I wonder how it is that people in captivity can be transferred from Iraq to Cuba without going through Shannon Airport.
"It would appear that it is happening and we're not of the mind to establish the truth or otherwise of that claim."
Socialist Party leader Mr Joe Higgins demanded that all US aircraft should be stopped and checked for terrorist suspects "on their way to Mr Bush's gulag in Guantanamo".
Caoimhghin O'Caolain of Sinn Féin said that the Government should make it known to the US that Ireland was no longer willing "to facilitate or subsidise the ongoing military actions in Iraq.
Fine Gael leader Mr Enda Kenny said that funding promised after 9/11 for an elite army ranger unit and the G2 military intelligence had not materialised.
The Fine Gael leader outlined the scenario that if a pilot flew a plane into the country on a suicide mission that it would be the Taoiseach's decision "to call in the RAF to shoot it down".
The Taoiseach said that the State groups covered the likelihood of several diverse emergencies occurring from marine oil spills to the recent foot-and-mouth disease crisis.
He added: "It's a small country... all of these agencies can pull together when required."