A second series of rolling three-day train strikes could now be averted after the union at the centre of the dispute at Iarnród Éireann responded postively to new proposals.
The leader of the ATGWU, Mr Mick O'Reilly, said he would recommend that striking train drivers accept proposals put forward after the National Implementation Body asked the Labour Court to intervene in the dispute today.
The proposals are expected to be put to the train drivers before the next series of strikes scheduled for this coming Monday if peace moves fail.
But SIPTU - which represents a large number of Iarnród Éireann workers - said it could anticipate "serious industrial relations difficulties in Irish Rail" if existing agreements and procedures are set aside in order to facilitate ILDA/ATGWU.
A SIPTU spokesperson said: "Our members who have abided by these agreements and procedures would quite justifiably feel that they would no longer be bound by them."
The National Implementation Body issued a statement to all sides in the dispute earlier today, separating the contentious issues into two categories.
The Labour Court was asked by National Implementation Body to investigate the procedures for dealing with individual disciplinary matters in Irish Rail.
The second issue - inter-union relations and union representation of train drivers - will be dealt with by the disputes committee of the Irish Congress of Trade Unions.
SIPTU and ATGWU representatives will attend the meeting.