The Republican attorney general of Texas sued the Biden administration on Wednesday to strike down its requirement that travelers wear masks at airports.
The suit comes as many governors, including in states governed by Democrats, have been rolling back mask mandates for indoor public settings as infections from the Omicron variant of the coronaviruses have plummeted following a record-setting surge last month. The federal government regulates forms of public transportation.
The federal mandate requiring travelers to wear masks has been extended several times since it was first introduced a year ago. Breaks for eating and drinking are allowed. Travelers younger than 2 and people with certain disabilities who cannot wear masks are exempt. Travelers who don't comply can be fined.
The suit was filed in federal court in Fort Worth. The mask mandate is unconstitutional and the Centers for Disease Control and Prevention lacks the authority to impose it. The Supreme Court declined to hear the case that sought to block the mandate.
Dr. Anthony Fauci, the nation's top infectious disease expert, said in December that he did not believe that masks would no longer be needed on planes.
The C.D.C. wouldn't comment on the suit.
The mask mandate for air travel has been questioned by some airline executives. Gary Kelly, the top executive of Southwest Airlines, said at a Senate hearing in December that he believed that the filters on the planes were sufficient and that masks did not add much protection. Mr. Kelly, who recently became the company's executive chairman after many years as chief executive, tested positive for the virus later that week.