British airlines must pay millions of pounds after the Supreme Court ruled that crew illness does not exempt them from claims for cancellation compensation.

The case in question dates back to January 2018, when Mr and Mrs Lipton had booked a flight with British Airways CityFlyer from Milan Linate Airport to London City. The flight was cancelled because the pilot reported feeling unwell shortly before departure.

The Liptons were rebooked on another flight and arrived at London City Airport just over two and a half hours later than expected.

They filed a claim for statutory compensation of £220. BA CityFlyer refused to pay. The case has gone to the highest court in the land for a final judgment.

The Supreme Court said in its ruling: “Although the amount involved is small, the decision could affect tens of thousands of claims brought each year under the applicable law.

Airlines can deny claims if they can prove that the cancellation was caused by “extraordinary circumstances which could not have been avoided even if all reasonable measures had been taken.”

But the unanimous verdict was that crew illness does not fall under this.

The judges stated that the purpose of Regulation 261, which governs air passenger rights, “is to ensure a high level of protection for consumers”.

The main question: “Whether the relevant event is inherent to the normal activity of the carrier”.

The Supreme Court held that crew sickness “cannot be classified as extraordinary”, saying: “That expression must be given its ordinary meaning, namely something extraordinary.

“Employee illness is a common problem for any business. Just as the wear and tear of the physical components of an aircraft is considered an inherent part of an airline’s operations, so too is managing employee illness.

“An event may be external to a carrier, but still inherent to its business operations. It is irrelevant whether staff become ill while they are not at work; their presence or absence from work is an inherent part of the carrier’s operational system.”

Passengers whose claim has been rejected in the past six years (in England and Wales; five years in Scotland) can now reapply for compensation.

Coby Benson, lawyer at Bott and Co, which seeks compensation for passengers on a no win no fee basis, said: “This decision is an important step forward in protecting the rights of airline passengers.

“Airlines must now take their responsibilities seriously and ensure they have sufficient staff to prevent such disruptions. And if such disruptions do occur, they must compensate passengers appropriately.”

The independent has asked British Airways and Airlines UK for comment.