The biggest airlines operating in the U.K. sued the government to overturn its requirement that people arriving in Britain self-isolate for two weeks amid the Covid-19 pandemic.

British Airways moved with budget airlines Ryanair Holdings Plc and Easyjet Plc to try to block the rules, which began Monday. They require travelers arriving in the U.K. to self-quarantine despite criticism from the airline industry that the move will stop lockdown-weary customers from booking summer vacations.

The government’s plan “will have a devastating effect on British tourism and the wider economy and destroy thousands of jobs,” the airlines said Friday in an emailed statement. They’ve asked for their judicial review to be heard as soon as possible.

British Airways’ parent IAG SA wrote to the Home Office to start a process to block the measure last Friday, but was left disappointed by the government response. On Friday, the Home Office declined to immediately comment on the lawsuit.

Prime Minister Boris Johnson is trying to balance the need for businesses to reopen with the risks of controlling the spread of coronavirus, which has hit the U.K. worse than any other European country. The government, which made a series of radical moves in March including ordering many businesses to shut, is now taking measures to ease lockdown and encourage the economy to start moving again.

Airlines have been some of the worst hit businesses. The International Air Transport Association on Tuesday predicted carriers will lose a combined $84 billion this year and almost $16 billion in 2021, its first estimate of the hit to earnings since the coronavirus crisis began. That compares with $31 billion during the 2008-2009 recession.

With infection levels on the decline in most European countries, governments have been easing travel restrictions, and beaches are opening in Greece, Spain and Portugal. Airlines are trying to salvage the summer season when tens of millions of people generally take their vacation.

The quarantine would torpedo BA’s plans to resume about 40% of its scheduled flights in July and force it to continue burning 20 million pounds ($25 million) a day, the carrier said. EasyJet is planning to resume some scheduled flights June 15, while Ryanair plans to restart flying July 1.