WASHINGTON, May 15—Senator Bernie Sanders (I-Vt.) led a letter with eight of his Senate colleagues to Ed Bastian, CEO of Delta Air Lines, condemning the corporation’s “insulting and demeaning” anti-union campaign targeting 40,000 of its employees. Sanders was joined by Senators Sherrod Brown (D-OH), Bob Casey (D-PA), Ron Wyden (D-OR), Tammy Baldwin (D-WI), Richard Blumenthal (D-CT), Ed Markey (D-MA), Elizabeth Warren (D-MA), and Jeff Merkley (D-OR).

Delta Air Lines’ brazen anti-union propaganda was widely criticized after a photo of the company’s poster was made public on social media. The Delta Air Lines’ flyer suggested that union dues would be better spent on video-game systems. A median full-time worker covered by a union contract earns 22 percent more in wages than a peer in a nonunionized workplace.

“Your attempts to deny the right of Delta workers to form a union is corporate greed, plain and simple,” conclude the Senators. “We urge you to end Delta’s anti-union tactics, make it clear to all of your managers that they should do the same, and allow Delta workers to decide the question of unionization free from fear, intimidation or retaliation.”

Read a PDF of the letter here.