Up to 44 cabin crew at Aer Lingus face being taken off the payroll in an ongoing dispute over new rostering arrangements.
A flight to Boston was cancelled yesterday as a result.
Twelve members of cabin crew, who are also members of the trade union IMPACT, were last night taken off their duties.
Management at the airline is holding meetings with another 32 workers and IMPACT expects they will also be removed from the payroll by this evening.
Spokesman Niall Shanahan said Aer Lingus is forcing the issue "unnecessarily".