Aer Lingus has threatened to suspend staff from the payroll on Monday if they fail to co-operate with cost cutting work practices being introduced without union agreement.
SIPTU has already described management's move as provocative and is balloting for industrial action.
In a letter to staff who are members of SIPTU, management outlined the changes applying to the individual employee.
Some of the changes may include staff being asked to move between sections during their shift, staff will be allocated six breaks and will be expected to remain at work for the full duration of all shifts. Rosters will also be altered.
Management adds that when all changes are successfully implemented, the current pay freeze will be lifted.
The letter warned it is a condition of employment that staff must comply with instructions and failure to do so will result in suspension from the payroll.
