ensure that it remains necessary, proportional, lawful and non-arbitrary.10 This does not exclude their right to bring proceedings before a court to challenge the lawfulness or arbitrariness of their detention.11 14. Detention in the course of migration proceedings must be justified as reasonable, necessary and proportionate in the light of the circumstances specific to the individual case. Such detention is permissible only for the shortest period of time, it must not be punitive in nature and must be periodically reviewed as it extends in time.12 15. Non-nationals, including immigrants regardless of their status, asylum seekers, refugees and stateless persons, in any situation of deprivation of liberty, shall be guaranteed access to a court of law empowered to order immediate release or able to vary the conditions of release. 16. Alternatives to detention must be sought to ensure that the detention is resorted to as an exceptional measure.13 17. Alternatives to detention should be realistic and must not depend upon the ability of the individual to pay for these.14 Alternatives to detention may take various forms, including reporting at regular intervals to the authorities, community-based solutions, release on bail or other securities, or stay in open centres or at a designated place.15 The conditions in any such open centres and other facilities must be humane and respectful of the inherent dignity of all persons.16 18. The application of measures alternative to detention must be reviewed by a judicial authority and alternatives to detention must not be considered as alternatives to release.17 19. The need to detain should be assessed on an individual basis and not based on a formal assessment of the migrant’s current migration status.18 The detention must comply with the principle of proportionality19 and as such, automatic and/or mandatory detention in the context of migration is arbitrary.20 20. Detention in the course of migration proceedings must be prescribed by law, justified as reasonable, necessary and proportionate in the light of the circumstances and reassessed as it extends in time. These cumulative elements must be complied with in each individual case.21 10 See A/HRC/30/37, para. 43; A/HRC/13/30, para. 61; and Body of Principles for the Protection of All Persons under Any Form of Detention or Imprisonment, Principle 11, para. 3. See also E/CN.4/2003/8/Add.2, para. 64 (a); A/HRC/13/30/Add.2, para. 79 (g); and A/HRC/16/47/Add.2, para. 120. 11 See A/HRC/30/37, para. 43; A/HRC/13/30, para. 61; Body of Principles for the Protection of All Persons under Any Form of Detention or Imprisonment, Principle 11, para. 3; and E/CN.4/2006/7, para. 85. See also E/CN.4/2005/6/Add.2, para. 86; E/CN.4/2005/6/Add.3, para. 86 (d); E/CN.4/2006/7/Add.3, para. 89. 12 See A/HRC/30/37, para. 45; E/CN.4/2006/7, para. 85; and A/HRC/10/21, para. 75. See also opinions No. 42/2017 and No. 28/2017; A/HRC/27/48/Add.4, para. 130 (h); A/HRC/30/36/Add.3, para. 73; A/HRC/30/36/Add.1, para. 81; A/HRC/36/37/Add.1, para. 99 (a); and general comment No. 35, para. 18. 13 See A/HRC/13/30, para. 59. See also E/CN.4/1999/63/Add.3, para. 33; A/HRC/19/57/Add.3, para. 68 (e); A/HRC/27/48/Add.2, para. 124; and A/HRC/30/36/Add.1, para. 81. 14 See, for example, A/HRC/36/37/Add.2, paras. 28 and 30. 15 See A/HRC/13/30, para. 65. See also A/HRC/30/36/Add.3, para. 48; E/CN.4/2003/8/Add.2, para. 64 (a) (ii); and A/HRC/36/37/Add.2, para. 92 (a) (ii). 16 See, for example, A/HRC/33/50/Add.1, para. 72. 17 See A/HRC/13/30, para. 65. See also A/HRC/36/37/Add.2, paras. 28 and 30. 18 See A/HRC/30/37, para. 115. 19 See, for example, A/HRC/19/57/Add.3, para. 68 (f) and (g); A/HRC/30/36/Add.1, para. 88; and A/HRC/36/37/Add.1, para. 99 (a). 20 See, for example, A/HRC/36/37/Add.2, para. 92 (a); and opinion No. 42/2017. 21 See general comment No. 35, para. 18; and A/HRC/10/21, para. 67. See also opinions No. 42/2017 and No. 28/2017. 3