Paris St Germain are ready to face Kylian Mbappe in a "legal forum" after the France forward refused an offer from the French football league's governing body (LFP) to mediate on a wage dispute, the Ligue 1 club said on Thursday.
While PSG welcomed the LFP's offer to mediate on Wednesday, the offer was refused by the France skipper.
French media reported the 25-year-old, who had a fallout with the club last year after refusing to sign a contract extension, is seeking around €55 million.
The Commission have suggested that Mbappe either go to an employment tribunal or settle the matter with the club where he spent seven seasons and became their all-time top scorer before making the switch to Real Madrid in June.
"Having heard the arguments of the parties yesterday, the Commission repeatedly insisted upon mediation between Paris St Germain and the player to find a compromise in light of PSG's favourable arguments," the club told Reuters.
"This mediation process has been refused by the player, contrary to the Commission's recommendation.
"...in light of the limitations of the Commission's legal scope to take a complete decision on this matter, the matter must now be contested in another legal forum, to which Paris St Germain is delighted to present all the facts over the coming months and year."
Last year they reported Mbappe had agreed to forego loyalty bonuses if he left PSG on a free transfer.
In January, Mbappe had said he made an agreement with PSG chairman Nasser Al-Khelaifi which would "protect all parties and preserve the club's serenity for the challenges ahead".
"As a matter of law and fact, the player has made clear, repeated public and private commitments that must be respected, having been afforded unprecedented benefits by the club over seven years in Paris," PSG added.
"The club looks forward to these being upheld in the proper forum, if the player seeks to pursue this incomprehensibly reputationally damaging matter further, in due course."
Mbappe's representatives were not immediately available for comment.