Art. 229. [legal definition and mandatory character of the collective labour agreement]
(1) The collective labour agreement is the convention concluded in writing between the employer or the employers’ organization, of the one part, and the employees, represented by trade unions or otherwise under the law, of the other part, establishing clauses on the working conditions, remuneration, and other rights and obligations arising from the employment relationships.
(2) The collective bargaining shall be mandatory, unless the employer has less than 21 employees.
(3) The parties shall be equal and free when they negotiate the clauses and conclude the collective labour agreements.
(4) The collective labour agreements, concluded in compliance with the legal provisions, shall constitute the law of the parties.