A powerful lobbying firm run by former Obama aides is running a campaign against open skies agreements, which have brought greater competition and lower airfares for Americans.

The firm SKDKnickerbocker, run by former Obama White House communications aides Anita Dunn and Bill Burton, is lobbying on behalf of legacy carriers Delta, American, and United Airlines. SKDKnickerbocker is one of several Democratic lobbying firms representing the Partnership for Open and Fair Skies, which for over two years has asked the federal government to freeze the routes of its competitors and end open skies agreements with Qatar and UAE.

The lobbying effort tried but failed to insert a provision in the final Senate tax cut bill that would have taxed Gulf carriers, opening the door for reciprocal taxes against U.S. airlines and cargo carriers, opponents of the tax said.

The legacy carriers—Delta, American, and United—have spent millions lobbying both the past and present administration to restrict the open skies agreements with Qatar Airways, Emirates Airline, and Etihad Airways. They say the Gulf carriers are unfairly subsidized, allowing for artificially low ticket prices.