Airlines have been warned that they could face fines if they do not tackle “harmful practices” fuelling chaos at UK airports, including selling more tickets than they can supply and not warning passengers about the risk of cancellations. In an open letter, the aviation and competition watchdogs told carriers they could be penalised if they are shown to be contributing to the misery of passengers hit by this summer’s widespread airport disruption. The warning from the Civil Aviation Authority (CAA) and the Competition and Markets Authority (CMA) follows weeks of last-minute cancellations and chaos at UK airports, with factors including Covid-related staff shortages, strikes and the war in Ukraine all adding to mounting anxiety that this summer’s getaways could now be under threat. The CAA and CMA told airlines they must fulfil their legal obligation to minimise the pain for customers or else face “enforcement action”, which could include fines. “We are concerned that some airlines may not be doing everything they could to avoid engaging in one or more harmful practices,” the regulators wrote. They said they were examining evidence of practices including “selling more tickets for flights than they can reasonably expect to supply and failing to warn consumers about the ensuing risk of cancellation”. Some airlines may not be offering alternative flights, including with rival airlines, in the event of a cancellation, they said. The CAA and CMA are also looking into whether airlines are giving passengers clear and upfront information about their rights when a flight is cancelled and giving them enough support and care during disruption. “If we receive evidence that consumers continue to experience these serious problems, the CAA, supported by the CMA, will consider further action, including enforcement,” they said. Passengers’ problems with cancelled and delayed flights and long queues have been compounded by shortages of airport staff after many were laid off during the pandemic. A senior executive at Heathrow warned on Thursday that these issues, which have forced the London hub to cap its passenger numbers this summer at 100,000 a day, could continue into 2023 unless issues including recruitment of baggage handlers and security staff are resolved. “We have more passengers than we have staff to cope with … I think there’s a lot that needs to be done over the next 12 months, the middle of summer … [so that] 2023 doesn’t face the same problems,” Nigel Milton told the UK Trade and Business Commission. The commission heard that recruitment of staff was an issue for airports abroad too, including Amsterdam’s Schiphol and Dublin, but the UK’s problems had been exacerbated by immigration restrictions. Milton and others have called on the government to put aviation on the skills shortage visa list, which allows certain professions to leapfrog the post-Brexit visa restrictions. He said such workers are “not viewed as being skilled, but they do require extensive training” and are in the most under-resourced areas. John Geddes, corporate affairs director at Menzies Aviation, told the commission: “We could bring people in from Spain, from Mexico … from eastern Europe to help out.”