Paris is cracking down. The city already restricts homeowners to renting out their homes for no more than 120 days a year, and officials are now taking Airbnb to court, with the claim that more than 43,000 homes listed on the site are unregistered with the government. If the city wins in court on June 12, up to 84 percent of Airbnb’s Paris rentals could be removed from the site, meaning travelers wouldn’t be able to book them—and people with existing reservations may not be able to contact their hosts.

Paris has been warning of possible legal action since December, when it became clear that the site wasn’t removing delinquent renters or those who don’t register online for a mandatory tax ID. Officials already fine Airbnb anywhere from $1,200 to $6,200 per home per day for listings that don’t have a tax registration number. The company paid out $1.6 million in fines last year—and has spent $603,000 so far this year—said the deputy mayor for housing, Ian Brossat, in an interview with Le Parisien. “Airbnb does not respect the law,” he said. “Airbnb has not made the slightest effort and has even explicitly refused to withdraw the ads.”

Airbnb’s response? “The regulation of holiday rentals in Paris is complex, confusing, and more suited to professionals than individuals,” the company said in a statement to AFP. “We encourage Paris to follow the path of other cities such as London, Berlin, and Barcelona, with whom we have worked efficiently on common-sense measures to promote responsible furnished tourist rentals,” it said. (The company has yet to respond to a request for comment from Condé Nast Traveler.)