Talks between Luas drivers and management have broken down at the Workplace Relations Commission.
It had been reported earlier that drivers had reduced their payclaim from 54% to 30%.
However this demand is still some distance away from the offer by management of 1% to 3% a year, with increased productivity.
SIPTU is reported to be considering all out strike action, as the dispute worsens.
Gerry Madden the CEO of Transdev who runs the Luas, hopes the union will reconsider: