New Delhi, March 3 -- Argentina's largest trade union group on Monday filed a lawsuit to block a sweeping labor reform promoted by President Javier Milei and aimed at radically altering labor relations in the South American country.

The reform, which was approved Friday by Congress, grants employers greater flexibility in matters of hiring, firing, severance and collective bargaining and seeks to limit the historical power of unions.

"This law represents a serious infringement of collective and individual rights that expressly violate constitutional principles," the General Confederation of Labor, CGT, said in a statement after its lawyers filed the complaint in the courts of Buenos Aires.

The complaint challenges the reform's constitu...