Pilots with Ryanair are being balloted for industrial action, the Irish Air Line Pilots' Association (IALPA) has said.
The association, which is a branch of the Fórsa trade union, cites a "lack of progress" in pay talks with the airline.
It said that the decision to ballot comes amid pilots' "frustration and disappointment" over the situation.
IALPA said it will continue engaging with Ryanair "in order to try and bring talks to a satisfactory conclusion".
In a statement, the union adds it is scheduled to meet with management at the airline next Tuesday, 30th July.
The ballot of pilots is due to be completed by Friday 9th August.
The British Airline Pilots Association is also balloting its Ryanair members on possible industrial action over pay & conditions.
In December 2017, Ryanair reversed its long-standing policy of not recongising pilot trade unions in a bid to avert threatened strike action.
Last year, Ryanair pilots with Fórsa held five days of strikes in a dispute over seniority issues and base transfers.
Following mediated talks, the pilots voted unanimously in favour of a collective agreement addressing the issues.
At the time, IALPA said the agreement was a "first step towards providing transparency and fairness for Ryanair pilots while also assisting Ryanair in recruiting and retaining pilots in the future".
