The Civil Aviation Authority warned airlines last week that it was not afraid to take action if airlines were not providing passengers with alternative flights or complying with compensation rules.

Of particular concern to the regulator is that airlines have sold tickets for timetables that were unrealistic. Bosses at the regulator last week wrote to airlines and airports to highlight concerns about the impact of staff shortages on flight disruption.

Officials have noted that while easyJet and BA have suffered widespread cancellations, rivals such as Ryanair and Wizz Air have emerged from the chaos comparatively unscathed.

Richard Moriaty, CAA chief executive, said airlines should schedule flights “on a basis that is deliverable given available staff and has resilience for staff sickness, including from Covid”.

Spokesmen for easyJet and British Airways said that they were complying with rules on looking after passengers and compensation.

Anna Bowles, the CAA’s head of customer enforcement, added: “Customers should be offered a choice of refund or offered alternative travel arrangements at the earliest opportunity. This can include flights on other airlines, or a new flight at a later date at their convenience. We also expect airlines to proactively provide passengers with information about their rights when flights are disrupted.

“If customers are concerned that airlines are not upholding their rights appropriately then they should complain to their airline. The Civil Aviation Authority will continue to monitor the situation, and where we see that airlines are systematically failing to provide consumers with their legal rights we will not hesitate to address this.”