and strike, as essential tools of the rights of association and freedom to organize, is fundamental. 126 115. In relation to the foregoing, this Court finds that the sphere of protection of the right to freedom of association in labor matters is not only subsumed to the protection of trade unions, their members and their representatives. Trade unions and their representatives enjoy specific protection for the effective performance of their functions, since, as this Court has established in its jurisprudence, 127 and as stated in various international instruments, 128 including Article 8 of the Protocol of San Salvador, in trade union matters, freedom of association is of the utmost importance for the defense of the legitimate interests of workers, and is part of the corpus juris of human rights. 129 116. In the instant case, given the failure of direct negotiations to reach a new collective agreement on working conditions, the STOJ initiated an economic-social dispute before the First Chamber of Appeals of Labor and Social Welfare. The conciliation procedure established in the Labor Code was followed, but concluded on February 15, 1996, without the parties reaching an agreement. Given this impasse in the negotiations, the STOJ filed a brief before the First Chamber of the Court of Appeals requesting that the General Labor Inspectorate be ordered to proceed with the count to determine whether the requirements to hold a legal strike under the Labor Code were met. 117. Indeed, according to Article 241 of the Labor Code in force at the time of the facts, in order to declare a strike lawful, the workers must “constitute at least two-thirds of the persons working in the respective company or production center, who have initiated their labor relationship prior to the collective economic or social dispute.” Moreover, pursuant to Article 4 of the Law of Unionization and Strike Regulations for State Employees, in its version in force at the time of the facts, for State workers to exercise the right to strike, the law established the prior requirement of having exhausted the direct procedure and subparagraph c) stated that “No strike may be carried out when it is intended to affect the essential services referred to in Article 243 of the Labor Code, Decree 1441 of the Congress of the Republic and others established by law, as well as those ordered by the Executive in compliance of the Public Order Law.” 130 118. In its advisory role, this Court has already pointed out that the criterion of legality of the strike is a central element with respect to the possibility of exercising the right to strike. Thus, the prior terms and conditions established by law for a strike to be considered lawful should not be complicated to the point of making it impossible, in practice, to hold a legal strike. On the other hand, this Court considers it possible for States to establish compliance with certain preconditions within the framework of collective bargaining before resorting to the strike mechanism in defense 126 Cf. Advisory Opinion OC-27/21, supra, para. 124. 127 Cf. Case Baena Ricardo et al. v. Panama, supra, para. 156, and Advisory Opinion OC-27/21, supra, para. 72. Cf. ILO. Convention No. 87 Freedom of Association and Protection of the Right to Organize, June 17, 1948 and Convention No. 98 Right to Organize and Collective Bargaining, of June 8, 1949. 128 129 72. Cf. Case of Baena Ricardo et al. v. Panama, supra, para. 158, and Advisory Opinion OC-27/21, supra, para. 130 Article 243 of the Labor Code established as essential services: “The following workers may not go on strike: a) workers of transportation companies, while they are on a journey and have not completed it. b) workers in clinics, hospitals, hygiene and public cleaning services; and those who work in companies that provide power, lighting, telecommunications and water processing and distribution services for the population, unless the necessary personnel is provided to avoid the suspension of such services, without causing grave and immediate harm to health, safety and public economy; c) the State’s security forces […]”. 34