Union leaders meet the Minister for Transport, Mr Brennan today, to outline their objections to his plans for a public transport shake-up.
Mr Brennan has announced plans to dismantle CIÉ and open up 25 per cent of the Dublin bus market to competition by the beginning of next year.
The plan has already led to one half-day strike by transport workers and further action is threatened unless the Minister engages in "meaningful consultations" with unions.
There was no indication last night that common ground had been found in advance of today's meeting.
The two unions involved, SIPTU and the NBRU, say a primary concern is that existing routes operated by Dublin Bus should not be transferred to private operators.
Mr Noel Dowling, national industrial secretary of SIPTU, said the unions were seeking wide-ranging consultations "on the whole transport sector".
They would make it "very clear" to the Minister that they were "not standing in the way of competition" as long as existing CIÉ company services were protected.
New operations outside the existing Dublin Bus area, for example, provided "a perfectly good model" of the way changes could be introduced.
Mr Liam Tobin, the general secretary of the NBRU, said there would be "trouble ahead" if the Minister did not engage in meaningful negotiations.
"We would hope that his calling us to a meeting means that that is going to happen, but it is difficult to know having regard to his statements to the media which suggest his plans are written in stone," he said.
A spokeswoman for Mr Brennan, however, said he had no wish to engage in confrontation with the unions. The reforms were designed to give the general public a more efficient, reliable and cost-effective transport service, she said. The Minister hoped they could be achieved in a spirit of co-operation.