228 | PRACTITIONERS GUIDE No. 6This notwithstanding, certain aspects of the Covenant rights, as regardsthe obligation to fulfil, are subject to the principle of “progressiverealisation” (Article 2.1 ICESCR), an acknowledgement that their fullrealisation might not be achieved immediately and that there may beresource constraints that should be taken into account when assessingState compliance with some of these obligations.3. Prohibition of retrogressive measuresArticle 2.1 ICESCR also prohibits States from taking retrogressive measuresin regard to the rights contained therein. 890 The prohibition ofretrogression “means that any measure adopted by the State that suppresses,restricts or limits the content of the entitlements already guaranteedby law, constitutes a prima facie violation. It entails a comparisonbetween the previously existing and the newly passed legislation,regulations and practices, in order to assess their retrogressive character.”891 A State adopting retrogressive measures breaches its ESC rightsobligations unless it can show that the measures:• were taken in pursuit of a pressing goal;• were strictly necessary; and• there were no alternative or less restrictive measures available. 8924. Non-discrimination and application to non-nationalsIrrespective of whether a particular obligation is of immediate effector is to be realised progressively, it must not be implemented so asto exclude or unjustifiably discriminate against non-nationals. Article 2ICESCR protects against discrimination in relation to the Covenantrights. The CESCR has made clear that the prohibition of discriminationalso includes discrimination against non-citizens on the grounds ofnationality. Although this is not an express ground, it is included under“other grounds” in Article 2.2 ICESCR. The Committee has stated that:“[t]he ground of nationality should not bar access to Covenant rights[. . .]. The Covenant rights apply to everyone including non-nationals,890 See, ibid., para. 9.891 ICJ, Courts and Legal Enforcement of Economic, Social and Cultural Rights, op. cit., fn. 29,p. 6.892 See, CESCR, General Comment No. 3, op. cit., fn. 147, para. 9. See, Free Legal AssistanceGroup and Others v. Zaire, ACommHPR, Communications Nos. 25/89, 47/90, 56/91,100/93, 19 th Ordinary Session, March 1996, para. 48 and holding; Acevedo Buendía et al.(“Discharged and Retired Employees of the Comptroller”) v. Perú, IACtHR, Series C No. 198,Judgment of 1 July 2009, para. 103; Miranda Cortez et al. v. El Salvador, IACHR, CaseNo. 12.249, Report No. 27/09, Merits, 20 March 2009, para. 105 (finding prohibition ofretrogressive measures under Article 26 ACHR); and, National Association of Ex-Employeesof the Peruvian Social Security Institute et al. v. Peru, IACHR, Case No. 12.670, ReportNo. 38/09, Merits, 27 March 2009, para. 140.
MIGRATION AND INTERNATIONAL HUMAN RIGHTS LAW | 229such as refugees, asylum-seekers, stateless persons, migrant workersand victims of international trafficking, regardless of legal status anddocumentation”. 893 An exception, permitting limitations on the applicationof the Covenant rights to non-nationals is given for developingcountries in Article 2.3 ICESCR. 894The CRC also includes protection against discrimination in regard to theESC rights of children protected by the Convention, including on thebasis of the child’s or the child’s parents’ national origin. The Committeeon the Rights of the Child has stated that “the enjoyment of rights stipulatedin the Convention is not limited to children who are citizens of aState Party and must therefore, if not explicitly stated otherwise in theConvention, also be available to all children—including asylum-seeking,refugee and migrant children—irrespective of their nationality, immigrationstatus or statelessness.” 895The Inter-American Court of Human Rights has ruled that the principlesof equality and non-discrimination, including on the basis of nationality,are peremptory norms of international law, (jus cogens) and thereforeimpose binding obligations on all States, to respect and fulfil them. 896As clarified by the Court, “the obligation to respect and ensure the principleof the right to equal protection and non-discrimination is irrespectiveof a person’s migratory status in a State. In other words, Stateshave the obligation to ensure this fundamental principle to its citizensand to any foreigner who is on its territory, without any discriminationbased on regular or irregular residence, nationality, race, gender or anyother cause.” 897The African Commission has held that measures depriving non-nationalsof rights which are not expressly guaranteed only to citizens (such asthe right to vote) will constitute arbitrary discrimination under Article 2of the African Charter, as “[r]ights under the African Charter are to beenjoyed by all, without discrimination, by citizens and non-nationalsresidents alike.” 898893 CESCR, General Comment No. 20, op. cit., fn. 22, para. 30. See also, Article 42, LimburgPrinciples, op. cit., fn. 888. Certain kinds of discrimination between citizens and non-citizensare also covered by Article 26 ICCPR, but the Human Rights Committee did not precise manycases of application. See, CCPR, General Comment No. 28, op. cit., fn. 22, para. 31.894 However, it is inferred that this provision was limited to end domination of certain economicgroups of non-nationals during colonial times. The fact that the exception is set only for developingcountries means that no other country can advance any exception on this ground.See, Articles 43–44, Limburg Principles, op. cit., fn. 888. Its application has been excluded forchildren by the CRC, General Comment No. 6, op. cit., fn. 138, para. 16.895 CRC, General Comment No. 6, op. cit., fn. 138, paras. 12 and 18.896 Advisory Opinion on Undocumented Migrants, IACtHR, op. cit., fn. 33, para. 101 (our emphasis)and holding at para. 4.897 Yean and Bosico Case, IACtHR, op. cit., fn. 281, para. 155.898 IHRDA v. Angola, ACommHPR, op. cit., fn. 395, para. 80.