The European Commission had brought the case on the grounds that such shares were a restriction on the free movement of capital within the European Union.
But the European Commission believes a quota on foreign players would be incompatible with EU law as it amounts to discrimination at work and a restriction on the free movement of workers.
Since the mechanism of a currency transactions levy is supposed to be based on taxing the net position of foreign exchange transactions, it could represent a restriction of the free movement of capital and payments (Article 63 TFEU).