The Minister for Public Enterprise, Ms O'Rourke, vigorously rejected Opposition demands that she be dismissed by the Taoiseachamid heated Dβil exchanges.

She accused the Opposition of being "indolent, led by lazy leaders", and challenged the party leaders to a public debate.

The Fine Gael leader, Mr Michael Noonan, she said, was "inert, inactive and unable", adding: "He appears to have exhausted himself in the course of the relentless whispering campaign he conducted against his former leader."

The Minister said that the Labour leader, Mr Ruair∅ Quinn, should realise there was more to politics than turning red and making his eyes bulge.

"Occasionally, just occasionally, he might consider lowering the mask of mock indignation, dropping the facade of fury and getting real."

The most momentous decision made by the Green Party, she added, was that it might be a good idea to have a leader.

The resignation motion was moved by Fine Gael, Labour and the Green Party and will be voted on tonight.

Mr Noonan said it was difficult to believe there were days when the very mention of State-sponsored companies such as Aer Lingus, CI╔ and Aer Rianta evoked a sense of pride and achievement among Irish people.

"All has been lost because of Government incompetence and mismanagement. The Government's shareholder representative is the Minister for Public Enterprise.

"Never has a Minister been more inappropriately titled. She has stifled enterprise, she has meddled where she did not belong, she has failed to give direction when that was appropriate and she has floundered, flustered and blustered when faced with criticisms of her performance."

The mismanagement and incompetence had taken many forms, he said. "The Minister has been indecisive, she has failed to deliver, she had presided over major cost overruns, she has managed sometimes to achieve the exact opposite to what she intended, she has served sectional interests, and she has ignored the future while pandering to the short-term needs."

On the proposed Luas scheme for Dublin, Mr Noonan said the only yard of track laid after 41/2 years had been the toy track in Merrion Square, laid as the latest political gimmick by a desperate government.

"In the process, incidentally, hundreds of people are being deprived of parking spaces and traffic congestion in the area has been increased. May I suggest that if the Minister wants to play with toy trains, she do so in the comfort of her homes in Dublin or Athlone."

Mr Quinn said the handling of the Aer Lingus crisis represented the straw that had broken the camel's back for the Opposition in respect of Mrs O'Rourke's record.

"The truth is that the Government is conspiring to push the airline to the brink of collapse. Since the crisis in Aer Lingus broke, it has done nothing to assist the company. In all of this Mary O'Rourke has been the Taoiseach's patsy." He said that the EU was to be the Government's fall guy for its failure to tackle the problems in Aer Lingus.

"It is a lie and there is no other way of putting it. Ireland has no formal application of any kind to invest in Aer Lingus before the European Commission. We are not looking for permission to invest in a viable airline. Europe exists solely as the Government's smokescreen for doing absolutely nothing."

The leader of the Green Party, Mr Trevor Sargent, referred to the manner in which the rail system had been run down. "Essentially, there is an inhumane side to the running of our public transport system, for which the Minister must take responsibility."