Apple filed an appeal over the European Union’s $587 million fine on Monday – escalating a showdown over enforcement of a sweeping antitrust law targeting Big Tech firms. EU antitrust regulators slapped Apple with the first-of-its-kind fine in April after finding CEO Tim Cook’s firm prevented rival app developers from quickly steering customers to services outside its App Store.

Apple took a challenge against EU regulators to Europe's second highest court on Monday after they fined it 500 million euros ($587 million) earlier this year for breaching landmark rules aimed at curbing the power of Big Tech.

Apple appealed a $580 million fine from the European Commission, which claimed that the company broke the rules controlling how app developers could communicate with users on Monday.