One of the Defensor’s most outstanding functions is that of supervising the activity of all public administrations: central, regional and local administrations. This supervision also encompasses the activity of public enterprises and the Administration agents or collaborators when they are performing public services or achieving public goals.

The Defensor del Pueblo can file appeal of unconstitutionality or appeal for legal protection of constitutional rights before the Constitutional Court. The Defensor monitors any violation of rights and can act on its own, opening actions or queries without waiting someone complains.

The Defensor del Pueblo, during investigations, can make recommendations and suggestions to authorities and officials in the Public Administration regarding the adoption of new measures and reminds them of their legal duties.

The Defensor del Pueblo prepares an annual report for the Parliament and publishes case reports on matters which require special attention. The Spanish Parliament attributed the functions of the National Preventive Mechanism against Torture (NPM) in Spain to the Defensor del Pueblo in November 2009.

The Defensor del Pueblo, in his or her capacity as NPM, performs preventive visits to all detention centers to detect problems linked to impunity of torture or ill-treatment. The conclusions of these visits are reflected in an annual report presented to the Spanish Parliament and the United Nations Subcommittee on Prevention of Torture in Geneva.

The Defensor reports to international and regional human rights mechanisms such as the UN and Council of Europe. The Defensor also promoting a culture of rights, through training and awareness raising activities on a variety of issues, such as the right to adequate housing, health or education and cooperates with NGOs, civil society, networks and regional bodies.