Which? is urging the aviation regulator to ban rip-off “no-show” clauses – which airlines can use to cash in when a passenger misses the first leg of a return flight.

The consumer champion has seen cases of passengers left stranded and hundreds of pounds out of pocket by carriers exploiting the little-known clauses.

All their connecting or return flights are then cancelled, typically with no refund given.

In some cases, airlines are effectively able to double their money by reselling the seats they cancel, with no refund given to passengers.

In December 2018, Which? wrote to nine airlines, including British Airways and Virgin Atlantic, informing them that the practice is potentially in breach of both the Consumer Rights Act and the Unfair Terms in Consumer Contracts Directive.

This is because the clause creates a “significant imbalance” between the airline, which stands to profit from the term, and passengers who face having to pay out considerable sums of money to rebook.

Flybe was the only carrier that pledged to make some changes in response, but it has not removed its “no-show” clause completely.

Which? had already secured commitments from Thomas Cook Airlines and Aurigny to scrap the terms, which have recently been ruled unlawful in Austria, before it wrote to the other airlines.

In a report released last week, the Civil Aviation Authority concluded that a policy of automatically cancelling a passenger’s return if they do not take the outbound flight is “disproportionate”.

It also said that “no-show” clauses used by some airlines – including British Airways – fell short of its expectations on “fairness and transparency” for consumers.

British Airways say that many of its tickets allow customers to make changes to their flights if they inform the airline before they travel, and stated that the policy is common practice in the industry, designed to stop “tariff abuse” – when passengers buy return tickets that are cheaper than a single flight.

Virgin Atlantic state that it will not cancel inbound flights where there has been a legitimate change in circumstances, provided the customer gets in touch first.

Despite its criticism, the regulator stopped short of taking any enforcement action to prevent passengers from getting ripped off by the practice.

Which? believes this decision puts the interests of airlines ahead of passengers, and is urging the CAA to put an end to the practice by enforcing an outright ban on the clauses.

Caroline Normand, Which? director of advocacy, said: “It’s totally unreasonable for an airline to cancel a passenger’s return flight – often without warning – simply because they’ve missed the first leg of their journey.

“Airlines have been able to cash in with this tactic for too long – leaving people miserable, stranded and hundreds if not thousands of pounds out of pocket.

“If airlines are not going to do the right thing and stop this disgraceful practice on their own, the Civil Aviation Authority should step in and ban these rip-off clauses.”