Section 281. All have the right to freely join a trade union. The law may restrict or except the exercise of this right in the Armed Forces or Institutes or other bodies subject to military discipline, and shall lay down the special conditions of its exercise by civil servants. Trade union freedom includes the right to set up trade unions and to join the union of one's choice, as well as the right of trade unions to form confederations and to found international trade union organizations, or to become members thereof. No one may be compelled to join a trade union.2. The right of workers to strike in defence of their interests is recognized. The law governing the exercise of this right shall establish the safeguards necessary to ensure the maintenance of essential public services.
Section 371. The law shall guarantee the right to collective labour bargaining between workers and employers' representatives, as well as the binding force of the agreements.2. The right of workers and employers to adopt collective labour dispute measures is hereby recognized. The law regulating the exercise of this right shall, without prejudice to the restrictions which it may impose, include the guarantees necessary to ensure the functioning of essential public services.