violate the basic right to liberty, and potentially, equality.182 Only in exceptional circumstances could short term detention, with attendant safeguards, be justified.183 Despite judicial decisions clarifying that deprivation of liberty on security grounds raises serious human rights concerns, policies, practice and debate in relation to FTFs reveal that it remains a live issue. Certain practices that have emerged in some states, such as short-term detention for questioning or to prevent imminent travel, house arrest or assigned residence, control orders or limitations on movement to and within certain areas, must be carefully assessed to determine whether they amount to deprivation of liberty. Whether or not such measures constitute deprivation of liberty depends on the degree of control and limitations to which the person is subjected to rather than their formal status as detainees or not, as is set out in legal standards.184 If the measures amount to deprivation of liberty, they must also be subject to all legal safeguards against arbitrary deprivation of liberty required under international human rights law. The right to be brought promptly before a judicial or other competent, impartial and independent authority applies immediately upon detention. Likewise, anyone whose liberty is restricted must have access to sufficient information concerning the grounds on which the measure has been imposed and enjoy due process guarantees to safeguard their rights.185 Such safeguards must be meaningful and sufficient in law and practice. While some states have taken the positive step of introducing prior judicial approval, if this amounts only to “automatic” judicial endorsement it would not necessarily provide meaningful oversight.186 182  This is clear from other contexts such as security detention of non-nationals in the United Kingdom post 9/11, see: A and Others v. The United Kingdom, ECtHR, op. cit., note 100. The French Conseil d’État issued an advisory opinion against preventive administrative detention on security grounds proposed in the aftermath of the terrorist attacks in Paris in November 2015, see: “Avis sur la constitutionnalité et la compatibilité avec les engagements internationaux de la France de certaines mesures de prévention du risque de terrorisme”, Conseil d’État, Assemblée générale, Section de l’intérieur, 17 December 2015, <www.conseil-etat. fr/Decisions-Avis-Publications/Avis/Selection-des-avis-faisant-l-objet-d-une-communication-particuliere/ Mesures-de-prevention-du-risque-de-terrorisme>. 183  The ECHR precludes this possibility under Article 5, which sets out an exhaustive list of grounds of detention, while the UN Human Rights Committee makes clear that such detention will be arbitrary save in the most exceptional circumstances, where the burden of proof to demonstrate the necessity rests on states, see: General Comment No. 35 (Article 9: Liberty and security of person), CCPR, UN Doc. CCPR/C/GC/35, 16 December 2014, para. 15 (hereafter General Comment No. 35, CCPR). 184  For an overview of case-law on this issue see “Guide on Article 5 of the Convention, Right to Liberty and Security”, ECtHR, April 2014, <https://www.echr.coe.int/Documents/Guide_Art_5_ENG.pdf>, pp. 4-5. On different forms of restrictions amounting to deprivation of liberty in the jurisprudence of the UN Human Rights Committee see also General Comment No. 35, CCPR, para. 5, op. cit., note 183. 185  See: “UN Body of Principles for the Protection of All Persons under Any Form of Detention or Imprisonment”, adopted by UN General Assembly Resolution 43/173, 9 December 1988, UN Doc. A/RES/43/173, See in particular principles 11-14 (right to be heard and provided with information), 17-18 (on legal counsel) and 32 (right to take proceedings to challenge the lawfulness of detention). 186  Ibid. Principle 4 requires that any form of detention and all measures affecting the human rights of a person under any form of detention shall be ordered by, or be subject to the effective control of, a judicial or other authority. 52 Guidelines for Addressing the Threats and Challenges of “Foreign Terrorist Fighters”