PSG's spokesman said: "Now that the appeals committee has confirmed the opinion of the legal committee, PSG has decided to take the case to the appropriate courts, while continuing to try to find an amicable solution with the player.
"In law and in fact, the player has made clear and repeated public and private commitments that the club is simply asking him to honour and respect in view of the unprecedented advantages he has enjoyed from the Club for 7 years in Paris.
"The club hopes that its word will be respected, knowing that if the player unfortunately decides to pursue this dispute, the club will be obliged to have it judged by the competent courts and to have the prejudice it has suffered and continues to suffer as a result of the incomprehensible position of its former player recognised. It is a question of good faith, honesty, upholding values and respect for the institution of Paris and its supporters."