SIPTU is warning that industrial action could be on the way for Dublin Bus and Irish Rail, as well as Bus Éireann.
The union is balloting members in Dublin Bus over a broken settlement deal, it's also in discussion with members of Irish Rail over broken agreements, and members in both companies have already pledged solidarity with their colleagues in Bus Éireann who are striking on February 20 over threatened cuts.
SIPTU Sector Organiser, Willie Noone, says if all three companies are ignoring their own agreements, they leave workers with no option but to take a stand.
"We have a dispute that we're going to execute in Bus Éireann on the 20th of February. We're also doing the very same thing now in Dublin Bus, they've a separate dispute because the company are breaking a WRC agreement which settled their last, recent dispute.
"Because that company hasn't honoured that, we're now going to take the action to bring Dublin Bus out and strike at the earliest opportunity.
" As well as that then we have a Labour Court recommendation in our rail, Irish Rail hasn't honoured that, so now we're going to take steps to start balloting people in Irish Rail."