Transport unions will meet today to discuss plans for industrial action that could begin within the next fortnight.
The unions are expected to discuss a co-ordinated campaign of action at a meeting at the Irish Congress of Trade Unions headquarters today.
Last night, the Minister for Transport, Mr Brennan, said he had written to CIÉ unions seeking to re-establish talks over the future of the company.
He said he was "strongly of the view" that the planned reforms could go ahead while protecting the terms and conditions of the workers in the company.
But the National Bus and Rail Union (NBRU) say the Mr Brennan's attitude to the talks made it impossible for them to attend meetings over the future of the company.
The NBRU general secretary, Mr Liam Tobin, said the union was available for talks, but only if they were facilitated by an independent chairman.