CBS Corp. filed a lawsuit accusing majority shareholder Shari Redstone of breaking her fiduciary duty to CBS shareholders.

CBS filed suit on Monday May 14 in Delaware Court of Chancery against Shari Redstone (president of National Amusements and vice chair of CBS and Viacom), accusing her of pushing for a merger with Viacom against the desire of CBS board members. By doing so, CBS is trying to dilute the stock owned by Redstone and her National Amusements holding company and prevent her from replacing the board members to complete the Viacom-CBS deal.

According to the accusations, the purpose of CBS is to obtain a restraining order that would barre Redstone “from abusing voting control and further harming CBS and its public stockholders in breach of their fiduciary duties”.