Porsche chairman Wolfgang Porsche is reportedly planning a coup against his cousin, Ferdinand Piëch to remove him from his post as chairman of Volkswagen.

According to a German news magazine, Focus, Porsche said that he is ‘horrified’ by Piëch’s behaviour.

The move suggests that there is a growing rift within the Porsche family over the direction in which the takeover of VW is heading.

Commenting on the actions of his cousin in a statement, Wolfgang Porsche, who is the sports car manufacturer’s largest shareholder and the chairman of Porsche Automobil Holding SE, said, “I am appalled with the voting behaviour of the supervisory board chairman.”

Tensions have to come to a head following a Volkswagen supervisory board meeting on Friday, which Piëch failed to attend. By not attending unions were able to outvote shareholders over the degree to which Porsche would be allowed to cooperate with Volkswagen’s Audi brand.

By abstaining from the vote to restrict Porsche management’s access to their Audi counterparts he appears to be gambling on retaining their support as he seeks to influence Porsche’s ownership of VW, a research note from Global Insight said.

The labour unions and workers council at VW is working on a number of strategies to limit Porsche’s influence on VW and creating blocks on management and technical collaboration between Porsche and the VW Group brands is one of the more extreme tactics that have been used so far.

Piech is the second largest individual shareholder in Porsche after Wolfgang Porsche himself, but despite this and the family connection, it appears that Wolfgang Porsche is now determined to remove his cousin from the position of the head of VW’s supervisory board. The Financial Times quoted sources close to the Porsche family as saying, “The family is deeply disgruntled. Mr Piech made them look like a fool and he is isolated now.”

There has been tension between Porsche and Piëch over the Porsche company taking control of Volkswagen. Porsche is the largest Volkswagen shareholder and is due to take a majority stake this year.

Piëch has strong support from Volkswagen unions who are concerned that the Porsche takeover will undermine their influence over the company.

Piëch is one of four Porsche family members on the board, and although Wolfgang Porsche has the support of the other three, his ability to oust Piëch will be limited by the fact that Piëch has the support of union representatives on the board.

Global Insight said that Porsche faces major obstacles in exerting full management autonomy over VW. The research firm noted that the VW Law means that the State of Lower Saxony has to agree with major management decisions while Piech’s sympathies with VW workers and anger at Porsche’s aggressive tactics also complicate matters.