Chelsea are ready to prove that midfielder Claude Makelele had told the French Football Federation he had retired from international football before he was called up for his country's Euro 2008 qualifiers.
The Premiership champions are astonished that France coach Raymond Domenech continues to insist he is unaware of Makelele's desire to quit the international scene because the player sent a letter to the FFF two days before he was selected.
Domenech maintains he has never seen Makelele's formal retirement note and, while that is strictly correct, the French footballing authorities were in possession of a faxed retirement document 48 hours prior to his call-up.
Makelele's selection has sparked a war of words between Chelsea and the French national team coach and the midfielder faces a four-match ban if he does not join up with his international colleagues for the qualifiers against Georgia and Italy.
His letter was faxed to the FFF on August 22 and the original sent by post on the same day.
In the document, PA Sport understands Makelele made it clear to the FFF that he no longer wished to be considered for international duty.
The letter read: 'It is with great regret and after much thought that I would like to inform the Federation that I would like to end my international career.'
Makelele goes on tell the FFF how proud he was to play for his country and to represent them in the World Cup final and that it was the right moment for him to retire from the international scene.
He also hoped they would understand his decision to quit and, after the letter was faxed, Domenech was informed of its contents in a meeting with Chelsea chief executive Peter Kenyon and coach Jose Mourinho later the same day.
Chelsea's proof is likely to win support within FIFA who have already hinted that a player is deemed to have retired if he informed his country of the decision prior to any call-up.
A FIFA spokesman confirmed a player is 'free' to decide that he is not playing for his national team.
Chelsea are now likely to furnish FIFA with copies of Makelele's letter and the timescale involved makes it highly unlikely the Blues will face any punishment if the player is prevented from travelling.
Mourinho accused France of treating the 33-year-old like a 'slave' by ignoring his wish to quit.
He declared: 'Makelele wants to retire but his national coach won't allow him to retire.
'In every country players can retire - like Figo, Paul Scholes and (Pavel) Nedved. In Portugal, England and Czech Republic, everybody can retire. The national team of France - they don't know the word `liberti'.'