Behind-the-scenes moves were taking place last night in a bid to avert the transport strikes planned for Thursday, which threaten to wreck the post-St Patrick's Day travel plans of thousands of people.
There was still no positive indication, however, that SIPTU was prepared to call off either a 24-hour public transport strike or a six-hour stoppage at airports.
It is understood the Taoiseach, Mr Ahern, was prepared to intervene with a request to have the strike called off, but only if there was a realistic prospect of the initiative being successful.
A Government spokeswoman confirmed last night that Mr Ahern had written to SIPTU in response to an approach earlier yesterday by the union's president, Mr Jack O'Connor. Details of the letter were not available.
The runways at Dublin, Shannon and Cork airports will close from 7.30 a.m. to 1.30 p.m. if the action goes ahead, leaving at least 25,000 air travellers facing cancellations or delays.
Ryanair is to challenge SIPTU's right to hold the strike in the High Court today.
Bus Éireann, Dublin Bus and Iarnród Éireann have each written to the union, asking it to call off the public transport strike.
In its letter, Dublin Bus said it condemned the planned strike "in the most forceful terms" and claimed that 500,000 customers would be affected.
"Action such as this threatens the financial security of the company, reduces customer confidence and damages our business in the long term," it said.
The threatened actions were also condemned by the Minister for Transport, Mr Brennan, and the employers' body, IBEC, which warned of damage to Ireland's reputation.
The Irish Hotels Federation said that the increased number of tourists in Ireland for the St Patrick's Day holiday, as well as "ordinary Irish people trying to go about their business", would bear the brunt of the action.
Informal contacts were continuing last night at the highest trade union and political levels with a view to averting the dispute.
An intervention by the Taoiseach was anticipated, but only if there was an indication that the strike leaders would be amenable to such an initiative. Mr Ahern persuaded SIPTU to call off its last threatened airports stoppage in January. Talks also took place yesterday between an Irish Congress of Trade Unions delegation and Department of Transport officials.
However, it is understood this meeting was primarily concerned with the longer-term talks process between unions and the Department, rather than attempts to get Thursday's action called off. SIPTU officials were not present at the meeting.
Both planned strikes are in response to what SIPTU claims is a lack of progress in separate talks with the Department about the futures of CIÉ and Aer Rianta.
The other main CIÉ union, the NBRU, says the talks are going well and it wishes to continue them.
Its members, however, will not pass SIPTU pickets on Thursday.
The full impact of the airports strike on intending passengers will become clearer today. Aer Lingus said it was drawing up a contingency plan which should be completed by late this afternoon.
Airlines had hoped, up to yesterday that Aer Rianta would be able to use outside personnel to replace fire-fighters who will be on strike on Thursday.
They held a second meeting with Aer Rianta about the issue yesterday.
The airports company insisted, however, that it had no option but to close the airport runways.
