The three CIÉ companies will move immediately to recoup wages paid to staff involved in yesterday's "no fares" protest, which provided a day of free public transport.
Iarnród Éireann, Dublin Bus and Bus Éireann are to write to the CIÉ unions on Monday informing them that the payment of wages to the staff concerned is to be referred to the Labour Relations Commission.
The three companies intend to pay the wages in the first instance, however, and seek to recover them with the assistance of the LRC.
CIÉ estimates that the action cost a total of €1.2 million in lost revenue, but decided earlier this week not to cancel services.
The protest was organised by unions to highlight opposition to plans by the Minister for Transport, Mr Brennan, to dismantle CIÉ and open 25 per cent of the Dublin bus market to competition by private operators by early next year.
While tens of thousands availed of the free travel opportunity, most people heeded the call not to exploit the action by undertaking journeys they would not normally make.
All three companies said last night that demand was generally no more brisk than usual, although Iarnród Éireann did have to turn away 60 people from two trains leaving Dublin. They were accommodated on later services.
In their letters to the unions on Monday, the companies will say that only staff who performed their full duties yesterday should be paid in full. This is described as an "important principle".
"Bearing in mind the particular nature of the action involved, the possibility of escalation in action which would affect services to our customers and consequent increase in industrial conflict, it has been decided to refer the question of payment of wages to the Labour Relations Commission for early consideration," the letters state.
In the meantime, they add, staff will be paid "normally".
It is understood that, whatever the outcome of any talks at the LRC, the companies want to put down a marker that unions cannot expect to hold further no-fares days without challenge.
The unions' next planned action is a day of protest, including demonstrations, on Tuesday, August 19th. One-day stoppages could follow on September 16th, October 14th and November 18th, all Tuesdays. A two-day strike is planned for Monday and Tuesday, December 8th and 9th.
The possibility of delaying payment of the first instalment of the new national pay round, due to CIÉ workers in October, has been discussed by managers in the companies. Such a move would be likely to inflame an already volatile situation, but a source in one of the companies said last night they could not afford a repeat of the revenue loss suffered yesterday. The letters to be sent on Monday will also state that the companies did not condone yesterday's action "in any way". Unions, however, hailed the action as a success and said they would not rule out repeating it.
Mr Liam Tobin of the National Bus and Rail Union said the action had proved the unions' case that there was huge potential in a low-fares public transport system.
"Mr Brennan should regard it as a free sampling day for the public and a glimpse of what can be achieved if he is prepared to channel the commitment of our members rather than throttle it," he said.
The general secretary of the Irish Congress of Trade Unions, Mr David Begg, described the action as an "intelligent protest".
"You have to understand that the people working in CIÉ are scared stiff about their future. They have to register some kind of protest," he said. However, the Taoiseach, Mr Ahern, said the action was "not very bright", and was a breach of the terms of Sustaining Progress.
"If people in semi-states, and particularly in CIÉ, think that forgoing fares for the day to damage the company is actually helping jobs, then they are wrong," Mr Ahern said. The protest was also criticised by the Tánaiste, Ms Harney.
A spokesman for Bus Éireann said it had been a "normal Friday" for the company in terms of demand, while Dublin Bus said there had been "no problems at all".
Iarnród Éireann said 40 people were turned away from the 4.30 p.m. Dublin to Waterford service, and 20 from the 5.20 p.m. service to Ennis, but all were accommodated on later trains. While there had been a significant increase in the numbers travelling from Sligo to Dublin yesterday morning, demand for most services had been normal.