Regulator says grounded passengers should seek €250 payout
The Irish aviation watchdog has encouraged up to 11,500 Ryanair passengers whose flights have been grounded to seek €250 compensation - despite the airline's refusal to pay out.
If they are successful, the airline could face a bill of up to €2.8m (£2.5m) bill just for Ireland.
And its costs could rise considerably this week as up to 100,000 passengers are hit by 600 flight cancellations due to strikes.
Holidaymakers are not guaranteed the compensation, but the Commission for Aviation Regulation said the onus is on the airline to prove it should not pay up.
The commission said passengers can look for compensation regardless of whether they have already received a refund or been re-accommodated on another flight.
Ryanair would have to prove that the strike was an "extraordinary circumstance" to avoid the payout.
Ryanair said it is not liable to pay compensation under the European air passengers rights rules, known as EU261.
"Ryanair fully complies with all EU261 legislation, however as these flight cancellations were caused by extraordinary circumstances, no compensation is due.
"Under EU261 legislation, no compensation is payable when the union is acting unreasonably and totally beyond the airline's control."