2. Necessity and proportionality Court in Celle held that the detention of a person was unlawful where the aliens department was unable, after a three months period, to inform the court whether (and how) they had sought to obtain the requisite documentation from the authorities of the State of return within the “necessary expedience”.82 the outset that the likelihood of successful removal is slim. This, as highlighted by the Estonian Supreme Court, could, for example, be the case of a stateless person, if there is no receiving state.84 It could however also be the case when countries of former habitual residence systematically deny admission to stateless persons who have left. In several countries, however, this research did not find any evidence that carrying out removal proceedings with due diligence is considered as a pre-condition in order for the detention to be justified. In this context, a central question relates to the threshold which needs to be fulfilled in order to consider that there are sufficient prospects for removal to justify ordering or maintaining detention. The Return Directive provides that detention can be maintained as long as removal arrangements are in progress and that it is necessary to ensure successful removal (Article 15.1 and 15.5). In Kadzoev, the Court of Justice of the European Union (CJEU; previously the European Court of Justice) clarified that a “real prospect” is required for the removal to be carried out successfully and that a reasonable prospect “does not exist, where it appears unlikely that the persons concerned will be admitted to a third country”. The ECtHR required “realistic prospects of expulsion”.85 Similarly, in its report to the Human Rights Council, the UN Working Group on Arbitrary Detention stressed that a legitimate aim for the detention “would not exist if there were no longer a real and tangible prospect of removal”.86 FRA Opinion To avoid situations that may be in conflict with the requirements of Article 5.1 ECHR as interpreted by the ECtHR, as well as with Article 15.1 of the Return Directive, EU Member States should consider including in domestic law the need to initiate and carry out the return and removal process with due diligence in order for the deprivation of liberty to be lawful. 2.4. Real prospects for removal Court of Justice of the European Union Kadzoev, 2009, paragraph 63 It should be pointed out that, under Article 15(4) of Directive 2008/115, detention ceases to be justified and the person concerned must be released immediately when it appears that, for legal or other considerations, a reasonable prospect of removal no longer exists. There are situations in which practical obstacles can substantially delay or obstruct the removal of a person. These can be within the sphere of responsibility of the migrant, such as for instance lack of cooperation to establish identity and nationality or outside his or her sphere of influence. Examples of the latter situation are the lack of cooperation from the consular representation of the country of origin, a situation of statelessness, or the mere absence of means of transportation. While in most cases the existence of reasonable prospects of removal will arise in the context of extending the period of detention,83 in some cases, it will be clear from 20 April 2009, case number 11Wx 38/09. 82 Germany/Oberlandesgericht [Higher Regional Court] Celle, InfAuslR 2003, 351-352. 83 In Denmark, for instance, the courts will typically examine whether the return proceedings are progressing and whether there are prospects of a return within a reasonable time frame. See Rigspolitiets Udlændingeafdeling, The legal foundation for return procedures and the practical return measures of the police [Det retlige grundlag for politiets udsendelsesarbejde i asylsager og politiets praktiske The following selected cases provide an illustration of approaches taken by national courts when defining the required threshold. In the UK, the Court of Appeal required ‘some prospect’ of being removed within a reasonable period in order for the power to detain to exist.87 It also indicated that “there must be something more than ‘hope’ that these negotiations would produce results”.88 In another case, the England and Wales High Court did not approve the continuation of detention after 10 months when “nothing but fruitless negotiations have been carried out”.89 Concerning documentation, udsendelsesarbejde], 2009, p. 10. (available in Danish at: http://www.politi.dk/NR/rdonlyres/81FB7CD9-47F7-4658-8D2852C4EF0D327B/0/Bilag1Detretligegrundlagapril.pdf ). 84 See the following cases by the Estonian Supreme Court: Estonia/ Riigikohus/3-3-1-45-06 (13.11.2006), para 10.-12; Estonia/ Riigikohus/3-3-1-6-06 (09.05.2006), paragraph 28; Estonia/ Riigikohus/3-3-1-53-06 (16.10.2006), paragraph 13. See also the test required in France (Footnote 66). 85 ECtHR, Mikolenko v. Estonia, No. 10664/05, 8 October 2009, at paragraph 68. 86 See Human Rights Council, 13th session, Report of the Working Group on Arbitrary Detention, paragraph 64 (UN General Assembly, A/HRC/13/30, 18 January 2010). See also the opinion by the Working Group in Mustafa Abdi v. United Kingdom of Great Britain and Northern Ireland, Opinion No. 45/2006, UN Doc A/HRC/7/4/Add.1 at 40 (2007). 87  Appellant A v. SSHD [2007] EWCA Civ 804, http://www.bailii.org/ew/ cases/EWCA/Civ/2007/804.html. 88 See R (on the application of I) v. SSHD [2002] EWCA Civ 888, at p. 206, paragraphs. 37-38, available at: http://www.bailii.org/ew/cases/EWCA/ Civ/2002/888.html. The case concerned a detainee who was awaiting deportation to Afghanistan at the end of his criminal sentence and where the Home Office was engaged in negotiations with neighbouring countries as at the time no flights from the UK to Afghanistan existed. 89  In re Mahmod (Wasfi Suleman) [1995] Imm AR 311, available online at: http://www.bailii.org/ew/cases/EWHC/Admin/1994/3.html. Mr Mahmod 25