E/C.12/GC/18 page 7 20. The fact that realization of the right to work is progressive and takes place over a period of time should not be interpreted as depriving States parties’ obligations of all meaningful content.13 It means that States parties have a specific and continuing obligation “to move as expeditiously and effectively as possible” towards the full realization of article 6. 21. As with all other rights in the Covenant, retrogressive measures should in principle not be taken in relation to the right to work. If any deliberately retrogressive steps are taken, States parties have the burden of proving that they have been introduced after consideration of all alternatives and that they are duly justified by reference to the totality of the rights provided for in the Covenant in the context of the full use of the States parties’ maximum available resources.14 22. Like all human rights, the right to work imposes three types or levels of obligations on States parties: the obligations to respect, protect and fulfil. The obligation to respect the right to work requires States parties to refrain from interfering directly or indirectly with the enjoyment of that right. The obligation to protect requires States parties to take measures that prevent third parties from interfering with the enjoyment of the right to work. The obligation to fulfil includes the obligations to provide, facilitate and promote that right. It implies that States parties should adopt appropriate legislative, administrative, budgetary, judicial and other measures to ensure its full realization. Specific legal obligations 23. States parties are under the obligation to respect the right to work by, inter alia, prohibiting forced or compulsory labour and refraining from denying or limiting equal access to decent work for all persons, especially disadvantaged and marginalized individuals and groups, including prisoners or detainees,15 members of minorities and migrant workers. In particular, States parties are bound by the obligation to respect the right of women and young persons to have access to decent work and thus to take measures to combat discrimination and to promote equal access and opportunities. 24. With regard to the obligations of States parties relating to child labour as set out in article 10 of the Covenant, States parties must take effective measures, in particular legislative measures, to prohibit labour of children under the age of 16. Further, they have to prohibit all forms of economic exploitation and forced labour of children.16 States parties must adopt effective measures to ensure that the prohibition of child labour will be fully respected.17 25. Obligations to protect the right to work include, inter alia, the duties of States parties to adopt legislation or to take other measures ensuring equal access to work and training and to ensure that privatization measures do not undermine workers’ rights. Specific measures to increase the flexibility of labour markets must not render work less stable or reduce the social protection of the worker. The obligation to protect the right to work includes the responsibility of States parties to prohibit forced or compulsory labour by non-State actors. 26. States parties are obliged to fulfil (provide) the right to work when individuals or groups are unable, for reasons beyond their control, to realize that right themselves by the means at their disposal. This obligation includes, inter alia, the obligation to recognize the right to work in national legal systems and to adopt a national policy on the right to work as well as a detailed