A Southwest Airlines Co. aircraft takes off as representatives and pilots of the Southwest Airlines Pilots’ Association (SWAPA) demonstrate outside Chicago Midway International Airport (MDW) in Chicago, Illinois, the United States, on Wednesday, May 18, 2016.

Daniel Acker / Bloomberg / Getty Images

The Southwest pilots union sued the airline this week, alleging the airline violated federal labor laws by changing labor rules during the travel downturn in the pandemic without negotiating the changes.

These included changes to working conditions and rules and tariffs for paying pilots, such as an “emergency” time off program, according to the lawsuit the Southwest Airlines Pilots Association filed in federal court in Dallas on Monday.

Southwest denied the allegations that its change required negotiations with the union.

“Southwest Airlines, like the rest of the industry, has been forced to respond to the unpredictable challenges of the global COVID-19 pandemic,” Russell McCrady, vice president of industrial relations for Southwest, said in a statement. “The airline contradicts SWAPA’s claims that all changes related to COVID in the past few months have required negotiations.”

The pilots union stated in the complaint that it was seeking an injunction to force the company to revert to the terms of its collective agreement.

The lawsuit comes as tension mounts between Southwest workers and management.

The Southwest Pilots Union said earlier this month it is considering picket lines at airports over Thanksgiving and Christmas to protest labor conditions.

The company announced last week it would cut its schedules for the rest of the year after employees complained of fatigue. Pilots and flight attendants have also complained about a lack of hotels and food options on the road.

Southwest announced to workers this week that it is negotiating an agreement with a “grocery delivery company” to deliver hot food to hotels during overnight trips.

“Southwest will pay for the monthly subscription to this service and we are negotiating to cut delivery charges and significantly lower service charges,” Rachel Loudermilk, director of base operations, wrote in an email to employees.