authoritative guidance on interpreting the provisions of the Covenant. In parallel, international experts, including the UN special procedures mandates holders, have contributed to developing a more comprehensive understanding of the rights and obligations contained in the Covenant to offer a more comprehensive and nuanced understanding of them. In affirming the ‘justiciability’ of ESC rights in particular cases, the jurisprudence of national courts and regional and international adjudication bodies has similarly demonstrated that the concepts and obligations underpinning ESC rights can be defined with sufficient precision to form legally binding and enforceable standards. 6 To begin with, the Maastricht Guidelines’7 affirmation that ESC rights impose three types of obligations on states is now widely accepted. They include the obligation to respect, to refrain from interfering with the enjoyment of ESC rights; the obligation to protect, to prevent violations of such rights by third parties; and the obligation to fulfill, to take appropriate legislative, administrative, budgetary, judicial and other measures towards the full realization of such rights.8 The long-standing perception that civil and political rights tend to primarily involve the negative obligation to respect while ESC rights focus more on the positive obligations to protect and fulfill—making them more resource intensive—has been gradually eroded. Both civil and political rights and ESC rights contain positive and negative elements to respect, protect and fulfill human rights, and many aspects of civil and political rights fulfillment are also heavily resource-dependent—such as creating a functioning judicial system that can ensure the right to a fair trial. Nevertheless the Covenant on Economic, Social and Cultural Rights differs from the Covenant on Civil and Political Rights in that it explicitly recognizes that fulfillment of these rights necessarily requires a significant investment of resources. Article 2(1) of the Covenant states that: Each State Party to the present Covenant undertakes to take steps, individually and through international assistance and cooperation, especially economic and technical, to the maximum of its available resources, with a view to achieving progressively the full realization of the rights recognized in the present Covenant by all appropriate means…9 This formulation allows for an element of flexibility that takes into account the fact that different countries have different resource bases, but was not intended to provide an ‘escape hatch’ that would allow governments to ignore their ESC rights obligations.10 Rather, this article simply provides a reasonable recognition that developing countries will necessarily make slower progress than wealthier countries. Accordingly, the realization of ESC rights will not be achieved at a uniform rate across all countries, but in ways that are consonant with different countries’ levels of development and available resources.11 When the Committee on Economic, Social and Cultural Rights first addressed the issue of state obligations in 1990 in its General Comment No.3, it dealt with the question of progressive realization by emphasizing that states have not only ‘progressive’ duties, but also ‘immediate duties’ under the Covenant, including to uphold the principle of non-discrimination, as well as to meet the ‘minimum core obligations’ contained in the Covenant and the provisions ‘capable of immediate application by judicial and other organs’ in many legal systems.12 The duty of non-discrimination is one of the fundamental principles underpinning human rights law. The Committee describes it as an ‘immediate and cross-cutting obligation’ under the Covenant.13 In addition to refraining from adopting discriminatory laws, policies, programs and expenditures, states Assessing compliance with the obligation to fulfill economic, social and cultural rights 3