Former Blackburn manager Sam Allardyce has instructed lawyers to initiate proceedings against his Ewood Park successor Steve Kean, Press Association Sport understands.
The action comes in relation to unguarded comments made by Kean about Allardyce to supporters while secretly being filmed.
The four-minute video, apparently filmed during Rovers' pre-season trip to Hong Kong last summer, was released on the internet overnight.
More top news
Manchester United are yet to make a decision on Radamel Falcao's future despite reports to the contrary.
Two men from Stockport are facing trial in Abu Dhabi after being arrested in the United Arab Emirates.
Under-fire Manchester City boss Manuel Pellegrini wants to be judged at the end of the season.