Wizz Air passengers who had flight disruption compensation claims dismissed by the airline are to have their cases reviewed under measures revealed by the industry regulator.

The Civil Aviation Authority (CAA), which has faced criticism for its oversight of the issue sector wide, said the Hungary-based carrier had committed to reconsider claims it received to cover the cost of replacement flights, transfers between airports, and assistance such as hotels.

It said all claims relating to Wizz flights operating to or from the UK, that were cancelled or significantly delayed and scheduled from 18 March 2022, would be automatically reviewed.

The regulator added that customers who believed they had a case ahead of that date could also file a claim.

The scheduled travel date had to be within the past six years to qualify, it said.

Wizz Air was the worst airline for UK flight delays in the past two years and the CAA said it had “significant concerns” over the volume of complaints and its treatment of passengers had been “unacceptable”.

Wizz had been instructed, it said, to make changes to its policies and procedures for how it treats passengers during disruption.

The company’s UK managing director, Marion Geoffroy, responded: “Last summer, like all airlines in Europe, Wizz Air faced unprecedented operating challenges, driven mostly by the external environment, including ATC (air traffic control) disruptions, airport constraints and staff shortages across the whole supply chain.

“As a result, we were unable to meet our own high standards of service.

“Flights were too often late or cancelled, disruption management overwhelmed our internal and external resources, and claims took too long to process and pay.

“We have learned from this experience and have taken significant steps to make our operation more robust and customer-centric.

“We expect this summer to be challenging for air traffic control, which will impact airlines.

“While we cannot anticipate every disruption, we have invested over £90m to prepare for increased air traffic.

“We are confident that we have taken the right steps to better support passengers this summer season.”

Rory Boland, editor of Which? Travel, said: “Wizz Air has an abysmal record on meeting its legal obligations under consumer law, racking up millions in pounds in county court judgments after continually failing to appropriately reroute passengers from delayed or cancelled flights and then refusing to reimburse those passengers for its failure.

“It is right the CAA is finally stepping in but it desperately needs to be given stronger powers to faster hold airlines to account.”