The Limburg Principles – widely accepted by human rights monitoring bodies – note that: ‘28. In the use of the available resources due priority shall be given to the rights-realisation recognised in the Covenant, mindful of the need to assure to everyone the satisfaction of subsistence requirements as well as the provision of essential services.’ Important principles of international law support this principle. First, human rights treaties are binding on States Parties and these must meet their obligations in good faith.87 Second, states cannot invoke domestic law as a justification for failing to meet a treaty’s terms.88 The obligation to accord ‘due priority’ to economic, social and cultural rights implementation leaves states a wide discretionary margin for deciding how to allocate available resources and has proved to be an extremely difficult obligation for international monitoring bodies to supervise.89 In reviewing state reports, the CESCR often simply asks states to raise budget percentages devoted to the social sector90 or indicate that the respective state has not prioritised its duties under the ICESCR.91 The CRC has also explicitly requested states prioritise budgetary allocations for implementing children’s economic, social and cultural rights, in both its General Comment No 19 and in several concluding recommendations.92 It also recommends that states specify the amount and proportion of the state budget spent on children’s rights, in order to allow evaluations on the impact of such expenditure.93 In the same vein, some special procedures have recommended that states reallocate government expending from military expenditure to spending on social sectors (eg, education and health).94 87 Art 26 Vienna Convention on the Law of Treaties: ‘Every treaty in force is binding upon the parties to it and must be performed by them in good faith.’ 88 Art 27 Vienna Convention on the Law of Treaties: ‘A Party may not invoke the provisions of its internal law as justification for its failure to perform a treaty.’ 89 Already in 1995, a CESCR member noted ‘if States Parties appearing before the Committee were to be asked what their priorities were, the Committee should ask itself whether it had the expertise to judge those priorities and whether or not it was qualified to judge a Government’s political choices. In a fully democratic society, which the Covenant was supposed to guarantee, how could the Committee challenge what the people demand?’ Adekuoye in E/C.12/1995/ SR.22, para 50. 90 See, eg, Concluding Observations Equatorial Guinea E/C.12/GNQ/CO/1 (2012), para 13; Concluding Observations Uganda E/C.12/UGA/CO/1 (2015); Concluding Observations Seychelles CRC/C/SYC/CO/2-4 (2012); Concluding Observations Thailand CRC/C/THA/CO/3-4 (2012), para 20. 91 See, eg, Concluding Observations the former Yugoslav Republic of Macedonia E/C.12/MKD/CO/2-4 (2016), para 15. 92 See, eg, Concluding Observations Guinea-Bissau CRC/C/GNB/CO/2-4 (2013), para 9. 93 See, eg, Concluding Observations Cyprus CRC/C/CYP/CO/3-4 (2012), para 16. 94 ‘Report of the Independent Expert on international order, Alfred de Zayas’ (Exploring the adverse impacts of military expenditures on the realisation of a democratic and equitable international order) (2014) UN Doc A/HRC/27/51, para 45; ‘Report of the Independent Expert on poverty, Magdalena Sepúlveda Carmona’, (2011) A/HRC/17/34, para 81. December 2017   The Obligation to Mobilise Resources: Bridging Human Rights, Sustainable Development Goals, and Economic and Fiscal Policies 39