Aer Lingus's decision to drop its Shannon-Heathrow service was unanimously condemned by members of Clare County Council at an emergency meeting last night.
Councillors called on Minister for Finance Brian Cowen and Minister for Transport Noel Dempsey to take action to bring about a change of mind by the company.
In an agreed statement they urged the Government "to take the necessary steps in the present Shannon/Aer Lingus crisis to ensure that development in the mid-west and west of Ireland generally be not disadvantaged or prejudiced in any way".
The mayor of Clare, Cllr Patricia McCarthy (Ind), told the meeting: "It is important that we are firm in our resolve, and that we have a unity of purpose."
County manager Alec Fleming said before the councillors agreed on the statement: "It has to be hammered home that the Heathrow route is just not another route."
Cllr Madeline Taylor Quinn (FG) claimed Mr Dempsey had "acquiesced in allowing Aer Lingus transfer the slots, and it is time that he woke up and took action and stopped this from going ahead".
Addressing the meeting, Shannon Regional Tourism Board chairman Michael Houlihan said the situation was the most serious faced by the region in his life.
"It is extremely important that we act in a unified way and speak with one voice."
Mr Houlihan said he believed there was a "heavy hand" behind the Aer Lingus move, "and we will be equally heavy in our response, and whatever legal action is needed, we are ready to move on it".
He claimed Mr Dempsey had abdicated his responsibility in not calling for an extraordinary general meeting of Aer Lingus shareholders.
Independent councillor Tommy Brennan said the issue would be resolved in the Dáil where there were enough TDs to vote against the Government.
"That is the only way it is going to be done to retain the slots," he said.