There's a power struggle brewing to control the $40bn media empire
Six board members of Viacom have pledged to fight any attempts to oust them as the struggle to control the group continues.
They signal that they will take legal action if the controlling shareholder, 93-year old Sumner Redstone, attempts to consolidate his power.
Board members have alleged that his decisions are being manipulated by his daughter, Shari Redstone - she called these allegations "absurd."
Lead Independent Director, Fred Salerno questioned the billionaire's mental competence and said that the removal of directors would be challenged.
Redstone removed Viacom CEO Philippe Dauman from the board of the firm that controls Viacom, as well as the seven-person board which will control its voting rights when Mr Redstone exits.
A statement from Mr Redsone's spokesperson last week said that he is considering replacing the Viacom board.
The has a number of lucrative media properties including Paramount Pictures, Comedy Central, MTV and Nickelodeon.
Legal experts consulted by Reuters said that the company's corporate charter gives Mr Redstone the power to immediately remove individuals from the company's board.
As the mental capacity of Mr Redstone is being examined as part of another legal case, so it is unlikely that courts in Delaware, where such a case would be heard, will explore the issue.