(Bloomberg) -- The closure of passenger air links between the U.S. and the U.K. will strip at least 11 billion pounds ($14.21 billion) off U.K. gross domestic product in 2020, according to a report commissioned by British Airways’ parent IAG SA, London’s Heathrow Airport, the Airlines U.K trade group and airport services firm Collinson Group.

The authors called for the creation of city or state-based travel corridors between the U.S. and the U.K. as well as airport testing for Covid-19. Keeping the routes closed will cost the U.K. economy 32 million pounds a day by the beginning of October, according to the report.

“Government inaction on aviation and its impact on Britain’s economy couldn’t be clearer,” British Airways Chief Executive Officer Alex Cruz said. “Ministers must reach agreement with their U.S. counterparts on a testing regime that minimizes quarantine and permits regional travel corridors to re-open the U.K.-U.S. market.”

Airlines have been campaigning to lift restrictions on trans-Atlantic travel which have been in place since early March. New York to London is BA’s most profitable route, with business travel a key driver of demand. The route generated about 7 million seat sales last year. The U.S. is the single biggest source of visitors to the U.K., with almost 4 million people visiting annually, according to the report.

While the U.S. currently doesn’t allow non-citizens who have spent any of the previous 14 days in the U.K. or Europe to enter, the U.K. mandates a 14-day quarantine on incoming travelers from the U.S. The Covid-19 pandemic has reversed decades of growth in the aviation industry, shutting down flights and triggering a slump that could see traffic diminished for years.

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