Passengers impacted by delays or short notice cancellation of their flight during the strike action four years ago can now claim for compensation from Ryanair, and they've been encouraged to do so by the UK's air travel regulator, the Civil Aviation Authority (CAA).

The low-cost airline has withdrawn a Supreme Court legal challenge, thereby ending the dispute over compensation for passengers impacted by cancelled flights due to strikes.

Ryanair had been challenging a decision of the Court of Appeal which ruled the strike action was not an "extraordinary circumstance" and compensation was owed.

An agreement was reached between the regulator and the airline at the end of last month, Ryanair said.

The settlement on 30 November agreed to end the "legal dispute concerning passenger rights", a spokesperson said.

"The resolution reached between Ryanair and the CAA is consistent with a recent ruling of the Court of Justice of the EU on union led strikes, ensuring a uniform level of passenger rights across the EU and the UK," the spokesperson added.

Paul Smith, consumer director at the UK Civil Aviation Authority said: "Ryanair's decision to discontinue the Supreme Court appeal of the Court of Appeal judgment means that affected passengers will now be able to make a claim for compensation from Ryanair if they were impacted by strike action taken by Ryanair pilots in 2018 and we would encourage all passengers on flights that were affected to claim the compensation they are entitled to."

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Thousands were impacted by the 2018 strike, which caused flight delays and cancellations, director of policy and advocacy at consumer group Which? Rocio Concha said.

They've faced a "protracted wait for the compensation they are owed", Ms Concha said.

"Ryanair must ensure money owed reaches affected passengers as soon as possible. No traveller should have to wait years for the compensation they are legally entitled to, and this episode underlines current weaknesses in the CAA's powers, as they are reliant on lengthy court action," she added.

Increased powers are needed for the regulator, Ms Concha said, adding: "The government must urgently set out plans for strengthening the aviation regulator's powers so it can hold airlines accountable."