A simmering dispute inside Lieff Cabraser Heimann & Bernstein has broken into a full boil, with the firm trying to force dissident partner Barry Himmelstein into binding arbitration as he petitions to have the firm dissolved.

Lieff Cabraser’s lawyer, Joseph McMonigle of Long & Levit, filed a petition to compel arbitration in San Francisco Superior Court last week. In it, the firm is tight-lipped about the nature of the dispute, saying that they’ve been negotiating the terms of Himmelstein’s departure since he took a leave of absence from work in August, but that they’ve reached an impasse.