[en] The purpose of this paper is to analyze the activity of collaboration legally provided of the Mutual and companies in the management of social security in order to determine the type of legal relationship which obeys under the "public" social security system required by the Constitution. To achieve this task, first, an historical examination of social legislation is made to signify the intervention that private individuals have had in the past in the management of social protection systems, and the evolution that have experienced these systems until the arise of social security. Then the current regulatory framework is presented, characterized by the assumption by the State of responsibility for the service of social security benefits and the legal provision that can collaborate in the management of social security the Mutual and companies, but without defining the kind of relationship which reflects the appropriate collaboration. Finally, it proceeds to legally qualify the partnership of private subjects in the management of social security based on the information supplied by the legal regulatory sources of superior rank -both internal character and internationally-, and jurisprudence the Supreme Court and the Constitutional Court. This qualification process concluded that this is a phenomenon of indirect management by private individuals of the public service of state-owned social security, being the legal title to legitimize this intervention the administrative concession regulated by the corresponding sectorial social security legislation.

[gl] O obxecto deste traballo céntrase en analizar a actividade de colaboración legalmente prevista das Mutuas e empresas na xestión da seguridade social co propósito de determinar o tipo de relación xurídica á que obedece no marco do réxime "público" de seguridade social esixido pola Constitución. Para a consecución desta tarefa, primeiro, realízase un exame histórico da lexislación social coa finalidade de poñer de relevo a intervención que os suxeitos privados tiveron no pasado na xestión dos sistemas de protección social, e a evolución que experimentaron estes sistemas ata o xurdimento da seguridade social. A continuación exponse o actual marco normativo, caracterizado pola asunción polo Estado da responsabilidade do servizo de prestacións de seguridade social e a previsión legal de que poden colaborar na xestión da seguridade social as Mutuas e empresas, pero sen definir o tipo de relación á que obedece a indicada colaboración. Por último, procédese a cualificar xuridicamente a relación de colaboración dos suxeitos privados na xestión da seguridade social sobre a base da información que subministran as fontes reguladoras legais de superior rango xerárquico -tanto de carácter interno como internacional-, como a xurisprudencia do Tribunal Supremo e do Tribunal Constitucional. Neste proceso de cualificación chégase á conclusión de que se trata dun fenómeno de xestión indirecta por suxeitos privados do servizo público de seguridade social de titularidade estatal, sendo o título xurídico que lexitima esa intervención o da concesión administrativa regulada pola correspondente lexislación sectorial de seguridade social.