The Taoiseach has told the Fianna Fáil Ard Fheis that the Government will ensure that Aer Lingus survives the current economic crisis in the best possible shape.
Mr Ahern told delegates at the start of the two-day conference at the City West Hotel a vibrant and viable airline was an integral part of the national infrastructure.
"Sooner rather than later, I hope and believe that the world will recover from the 11th of September and its on-going aftermath. We cannot allow a situation to arise where Ireland is no longer readily accessible from our main training and tourism centres. This would be a national disaster and one I pledge not to allow."
Mr Ahern was also scathing on the recent decision by the British Government to develop a Mixed Oxide (MOX) plant on the Sellafield site.
He described the facility as the "single most serious threat to our environment".
"This surviving dinosaur of a defunct military industrial conflict is being kept on life-support by a huge write off of British Taxpayers funds.
"It has all the hallmarks of a bad news story hastily released in the midst of a momentous international crisis in the hope that most people will be distracted. It poses a significant additional and totally unacceptable threat to our environment and to our national security.
"In the context of the heightened threat from terrorism the existing risks from Sellafield are unacceptably increased.
"The opening of the Mox plant would mean that the Irish Sea is used as a highway for the transport of highly dangerous nuclear fuel to and from nuclear plants around the world. And this is in addition to the existing and equally unacceptable activities of Sellafield.
"The position of Fianna Fáil is clear . . . we demand Sellafield be shut".
The Ard Fheis continues tomorrow.