SIPTU has said an all out strike is now possible after Luas operator Transdev warned of potential temporary lay-offs
Passenger representatives say they have been forgotten in the midst of the continued row over pay at the Luas.
An all out strike now appears to be on the cards after Transdev and SIPTU failed to break the deadlock at last ditch talks yesterday.
Luas workers are now expected to be put on protective notice later today as the dispute escalates.
The union says they have been told that pay deductions and temporary lay-offs may be used as a possible way to recoup losses sustained from repeated strikes.
Mark Gleeson of Rail Users Ireland is urging SIPTU to be more realistic.
"We're in very dangerous territory currently," he explained. "It looks like we may be facing an all out Luas strike.
"Transdev have clearly indicated that their financial position is going to become untenable and they may need to make further cuts. So we may end up with no Luas service for a substantial period of time," he added.
John Murphy is organiser for the SIPTU transport sector.
He told Newstalk Breakfast the management have "leveled a number of threats" against staff.
It was reported yesterday that Luas drivers have indicated they wanted increases of up to 18% over a three-year period, including a long service increment of about 7%.
Transdev has previously suggested that the original Workplace Relations Commission pay offer to drivers is no longer on the table after it was overwhelmingly rejected by union members.
The next strikes are due to take place on April 23rd and 24th.
These will be followed by further stoppages on April 28th, May 4th, May 13th, May 20th, May 27th and a partial stoppage on May 26th.
Meanwhile, Luas drivers have been accused of sparking a pay crisis in the public sector.
Dr Ed Walsh is the Founding President of the University of Limerick. Speaking to Pat Kenny, Dr Walsh said the drivers' demands have set a bad example for other workers.
"They have inflamed the whole industrial relations situation in Ireland," he argued.
"Dublin Bus are now looking for pay parity with Luas. Irish Rail [has seen a] 25% claim, gardaí are unhappy, the teachers for new entrants are looking for a 30% claim... And the local authority Councillors, god bless them, are looking for a 39% increase," he added.