The company says it "remains in an extremely difficult financial position"
Iarnród Éireann has criticised trade unions representing DART drivers for withdrawing from discussions at the Workplace Relations Commissions.
Management and unions had been due to attend talks tomorrow aimed at averting industrial action over a new 10 minute service, which is due to come in on April 10th.
However, SIPTU and the NBRU have withdrawn from the negotiations - saying they will not discuss rosters without a discussion about pay too.
The move has been described by Iarnród Éireann as 'deeply regrettable'.
In a statement, the company says "it is through our timetable that we provide our customers with the services they require.
"It is notable that during the recession, when DART frequency was reduced, roster and timetable changes were accepted without issue, but as we seek to restore DART services in line with demand our trade unions refuse to engage with the company," they add.
The company says it "remains in an extremely difficult financial position and we will only emerge from this by ensuring our business can grow in line with demand and through meeting our customers’ requirements".
The dispute began last October when Iarnróid Éireann first proposed increasing frequency on the service.
In response, the National Bus and Rail Union organised a two-hour stoppage, and the plan, which was supposed to begin in January, was postponed to April.
DART drivers have already been balloted for strike action in the event the company introduces the new timetable.
Pay claims have also been lodged at Bus Éireann and Dublin Bus.