SIPTU has said that a threat by Transdev to dock the pay of Luas drivers is an outrageous and provocative escalation of the dispute.
The Luas operator said it will reduce drivers wages by 10% from this Friday if their strike continues.
The union representing the drivers has said that the reduction in pay would be illegal as its members are involved in a lawful industrial dispute with the company.
Transdev says the move is necessary to recoup costs incurred as a result of the stoppages.
SIPTU's divisional organiser Owen Reidy said it will be challenged, however.
“it is, in our view, in our opinion, illegal, and we would challenge them on that,” he said.
“I think he’s going to breach the Payment of Wages Act. You cannot, willy-nilly, pickpocket workers’ pay without due regard.
“It is morally wrong, and it’s an escalation of a dispute that does not need to be escalated, and I think it’ pouring fuel on the fire.”
Transdev managing director Gerry Madden says he is satisfied that the decision does not break any laws, however.
“This is to do with work-to-rule for a start, so that’s what will be happening from Friday,” he said.
“But I can assure you that while I’m no legal expert myself, I would not have taken such action myself without getting very, very senior legal counsel, and I’m very comfortable with that.”