The CAA said the budget carrier had rejected passengers’ legitimate claims for compensation under EU Regulation 261 after hundreds of Ryanair flights were affected by industrial action in the summer.

While passengers have been able to escalate their disputes to CAA-approved body body AviationADR, which provides alternative dispute resolution for complaints, the CAA says Ryanair has decided to terminate its agreement with AviationADR.

The CAA maintains the strike action that caused the delays in the summer did not constitute “extraordinary circumstances” and therefore did not exempt Ryanair from paying EU261 compensation.

In a statement issued on Wednesday morning, the CAA said: “The UK Civil Aviation Authority has today started enforcement action against Ryanair, following the airline’s decision that financial compensation is not payable under European Commission Regulation 261/2004 for flight disruption resulting from industrial action by the airline’s staff this summer.

“Ryanair passengers have made claims for compensation directly to the airline, but these have been rejected. Passengers have then been able to escalate their complaints to AviationADR, a body approved by the Civil Aviation Authority, to provide alternative dispute resolution for passenger complaints.

“Ryanair has now informed the Civil Aviation Authority that it has terminated its agreement with AviationADR. As the Civil Aviation Authority said at the time of the industrial action, in its view, the strikes were not “extraordinary circumstances” and were not exempt, meaning consumers should be compensated in accordance with Regulation EC261/2004.

“As a result of Ryanair’s action, passengers with an existing claim will now have to await the outcome of the Civil Aviation Authority’s enforcement action.”

The CAA says any strike-related compensation claims made through AviationADR have been put on hold awaiting the outcome of the enforcement action.

Passengers with new claims, or who are not satisfied with the outcome of theirs or have not received a reply from the airline within eight weeks, should contact the CAA’s passenger advice and complaints team.

A Ryanair spokesperson said: “Courts in Germany, Spain and Italy have already ruled that strikes are an “exceptional circumstance” and EU261 compensation does not apply. We expect the UK CAA and courts will follow this precedent.”