While Uralkali is seeking the return of sponsorship monies paid to Haas, the American F1 team is looking for compensation for "loss of profits".
In the aftermath of last month's invasion of Ukraine by Russia, Formula One was among one of the first sport's to be affected by the global sanctions that followed.
Along with the dropping of Russia's round of the Formula One World Championship, teams sought to sever all ties with Russian funding, among them Haas.
As well as ending its association with title sponsor Uralkali, the American team dropped driver Nikita Mazepin, son of the potash giant's owner.
Uralkali subsequently requested the return of £9m ($12m) it had paid the American team in advance of the 2022 season.
However, in its response, Haas has not only refused to hand back the money, it is claiming a further £6.6m ($8.7m) in compensation for "loss of profits".
In a further twist of the knife, the American team insists that until the compensation is handed over it is refusing to adhere to a clause in the original contract which stipulated that Mazepin would be given one of his (2021) cars - assuming there is one left in one piece.
In addition, the team is refusing to pay the Russian driver for any work carried out for the team this year up until the time of his sacking.
According to Motorsport.com, Dmitry Mazepin's ties to the Kremlin, and thereby Vladimir Putin, in tandem with the sanctions imposed by the European Union, were enough to triggered a disrepute clause in the contract.
"According to unanimous legal scholars and case law, the party which terminates the agreement for breach of the other party is under no obligation to return to such party what it has already received under the agreement," states a letter from Haas to Uralkali, according to Motorsport.com.
"The claim of Uralkali to obtain the re-payment of the down paid amount of EUR 12,000,000 is therefore ungrounded and rejected."