Consumer watchdog Which? has warned travellers not to book flights until clarity emerges over international travel after revealing more than two million passengers lost money during Covid.

The warning came amid research which found people were left out of pocket after missing flights that continued to operate during the pandemic.

The watchdog said local Covid lockdowns or restrictions at destinations prevented many passengers from travelling.

But because the flights continued to operate they were not entitled to a refund.

Which? said 2.3 million people across the UK lost out, despite circumstances which meant they could not reasonably – or even legally – travel to their destination.

Anyone considering booking flights for this summer should hold fire, it said.

“Wait until the situation around international travel becomes clearer,” Which? said. “And when the time comes, book a package holiday rather than a flight-only booking for stronger passenger protections, and only with a trusted provider that offers a generous and flexible booking policy.”

Which? Travel Editor Rory Boland said: “For almost a year now, Which? has been hearing from frustrated passengers who’ve been left out of pocket for flights they were unable to take, often through no fault of their own, because the flight went ahead as scheduled.

“While some have successfully been able to claim on their travel insurance or through their bank, others have been left high and dry.

“With non-essential travel currently illegal, airlines must play their part in protecting public health by ensuring no one is left out of pocket for abiding by the law and not travelling.

“All airlines should allow passengers the option to cancel for a full refund, as well as fee-free rebooking options, while these restrictions remain in place.”

Almost half of those who lost money said they could not travel because of national or regional lockdown rules which instructed them to stay at home.

Others were only given the choice of rebooking their flight or losing their money.

Which? said rebooking may have meant paying a significant fare difference if the new flight was more expensive.

Customers also faced the dilemma of ‘trying to choose new dates without knowing when international travel is likely to resume again’.

Just over a quarter (27%) of those left out of pocket said they were unable to fly because of restrictions in place at their destination that would prevent them from entering the country.

Nearly four in 10 said they could not travel because the FCDO had advised against all non-essential travel to their destination.

“While those with package holidays would have had their bookings cancelled by the provider in these circumstances, entitling them to a full refund, many airlines continued to operate flights to countries with an FCDO warning against non-essential travel, on the basis that they needed to operate them as scheduled in order to facilitate essential travel,” Which? said.