Monaco risk being kicked out of the French league if the principality club fail to comply with new rules that will end the financial advantages they have enjoyed.
An agreement made in 1869 means Monaco, currently top of Ligue 2, can employ a foreign player without him having to pay income tax.
That effectively allows the club to pay significantly higher wages than their French counterparts, who are subject to harsher tax laws.
Although French players at Monaco are subject to French income tax regulations, they pay approximately 20% less in national insurance contributions on their salaries than their French-based opponents.
The French Football League's (LFP) administrative council voted unanimously on Thursday to change league rules to require all clubs competing in the French game to be subject to the same financial rules, giving Monaco until June 1 next year to comply.
Failure to do so could see the club excluded from LFP competition.
Noel Le Graet, the French Football Federation (FFF) president, told L'Equipe: "I don't think it will come to that. There are agreements between France and Monaco, there's a tradition.
"It's a case which will no doubt come before the federation. It's the sort of issue in which everyone is right. Monaco want to play in the league. The clubs consider, quite rightly, that there's an economic issue. How do you find a consensus?"
L'Equipe recently published minutes of a January meeting of the LFP administrative council at which it was suggested that "all participating clubs be subject to the same fiscal and social conditions".
The paper reported former Monaco president Jean-Louis Campora, currently an advisor to Monaco's Russian billionaire owner Dmitri Rybolovlev, as saying: "In this affair, only one club is being aimed at: ours.
"After taking advice, we're going to take measures to stand up for our rights. We're going to contest this shocking decision."
Campora had initially been invited to attend Thursday's meeting to put his club's case, but was then told that he was no longer welcome.
"I was surprised, shocked even, that I was told not to come by email at 19:30 just the day before," he explained.
"I'd been invited to give Monaco's point of view. So it's without a representative of the club being heard that it's been decided to change the competition rules."