A number of Cityjet staff at Dublin Airport are taking limited industrial action in a dispute over pay.
Irish Cityjet crew and pilots, represented by trade union Unite, rejected a pay offer from the airline last month.
The union confirmed on Wednesday that as a result they are currently operating a work-to-rule that involves allowing the company less flexibility with rostering.
Cityjet did not comment on the dispute, but a spokesman said that none of its its services had been disrupted.
The union’s action means that pilots will not switch from one scheduled flight to another should Cityjet require them to do so.
Unite said that the action had been under way for a number of days and that it was begining to have an impact. The union said that the dispute is over the company's refusal to go to the Workplace Relations Commission (WRC) to resolve a dispute over a claim for a pay increase.
The company said last month that the issue of pay and conditions had been before the WRC for some time.