The Taoiseach has asked both sides to think about customers
The Taoiseach Leo Varadkar has called on Ryanair management and unions to "come to an agreement" amid planned ongoing strike actions.
It comes as the carrier is to cancel 20 flights to and from Ireland next Friday.
This will be the fourth day of strike action by Dublin-based pilots.
It said all customers have already been notified and will be readily re-accommodated on other flights – or refunded their fare.
Trade union Fórsa said more action could follow unless the airline's management "changed tack" and "negotiated in good faith" on the issue of base transfers and related matters.
While the airline also warned on Wednesday that up to 300 jobs are at risk, with plans to cut the size of its Dublin fleet.
In a statement, Fórsa said it believed the airline's decision to issue protective notice to 300 of its staff on Wednesday was "an attempt to put pressure on its employees."
It said the "provocative act, which was likely to harden pilots’ resolve, had escalated the dispute while demonstrating management’s unwillingness or inability to negotiate with unions in good faith."
Ryanair has issued letters of 90 days protective notice to over 100 pilots and over 200 cabin crew employees.
It said their services "may not be required" from October 28th onwards, due to this reduction in the winter fleet.
Speaking in Rome after meeting the Italian Prime Minister Giuseppe Conte, Mr Varadkar said: "Ultimately it's a commercial decision for any business as to how many flights they're going to run or how many staff they need to staff those planes - so that is a commercial decision.
"But I am very concerned at the escalation in the Ryanair dispute, particularly the impact it's going to have on holidaymakers - on every day people who have spent months saving up for their holidays who may now find themselves discommoded or rescheduled or perhaps not being able to take that holiday.
"So I'd really ask both Ryanair and the unions to think about the people, to think about those customers: the ones who ultimately pay the wages of the pilots and the cabin crew, who ultimately pay the dividends of the shareholders and keep the board in office.
"I'd ask that they get around the table, come to an agreement and allow things to return to normal".