This story was updated at 4:24 p.m. EDT.
Federal labor regulators this week issued a formal complaint alleging that the National Audubon Society violated labor laws, including by failing to provide information to its employee union and by extending some benefits only to non-unionized staff.
The National Labor Relations Board issued a complaint and notice of an upcoming hearing in an ongoing dispute between the New York-based conservation group and its staff union represented by Communications Workers of America.
The complaint comes as the Bird Union-CWA Local 1180 and Audubon have struggled to finalize a collective bargaining agreement for more than two years after staff unionized. The employee union recently voted to authorize a strike over the ongoing disputes surrounding pay and benefits.