Aer Lingus has carried out a review to identify staff who have taken too many holidays since April.
In recent months, the airline cut pay and hours to 30%, which also reduced leave entitlement.
On a memo to staff, the head of Dublin Airport operations told staff: “The review of annual leave taken since April 1 against the reduced hours that employees have been working has identified a number of employees who have exceeded their annual leave entitlement.
“We will now start to make contact with these individuals to discuss the issue and put in place a plan going forward to address the issue.”