The NFL Referees Association filed an unfair labor practice charge against the league with the National Labor Relations Board on Thursday.
In the complaint, the NFLRA alleges that the NFL has sent letters to officials that “contained inaccurate, false and incomplete information” about the bargaining. Labor negotiations between the two sides broke off on June 3.
The two sides had nine bargaining sessions since October before two mediation attempts failed. The NFL said that it would begin hiring and training replacement officials.