LEGAL BACKGROUND The following section of the report will briefly cover policy and legal structures regarding human rights, asylum procedures and reception conditions in detention on both a European and Greek level. This will be channelled into the legal context for both applicants of international protection and third country nationals subject to return orders. This provides the foundations on which to understand the extensive discrepancies between European structures and practices in Greece. People on the move are particularly vulnerable to deprivation of liberty on both criminal or administrative grounds, which is often used by states to discourage irregular migration. Criminal charges may be based on the use of false documents or leaving their residence without authorisation. However, administrative detention is commonly used for irregular third country nationals, in connection with violations of immigration laws, for example, for overstaying an expired permit. Importantly, the purpose of administrative detention is to ensure that another measure, such as deportation or the asylum procedure, can be carried out. There are also many instances of administrative detention based on other grounds, such as public security. Administrative detention results in individuals being normally detained in special facilities - PRDCs in Greece - rather than in judicial prisons. This research focuses on the administrative detention of third country nationals and asylum seekers, rather than those held on the grounds of criminal charges, although some of the people we spoke with had also experienced detention for criminal reasons. This regards both applicants of international protection, and those detained in view of removal, the two legally defined groups that this report focuses on. Basic Principles & Legal Structures for the Detention of Applicants of International Protection Detention is a severe interference with the basic human right to liberty and as such can only be applied in very specific circumstances and conditions. Therefore, there are several basic principles that need to be taken into account when considering whether an asylum seeker should be detained. Detention of asylum seekers can only be implemented as an exceptional measure, in very clearly defined circumstances.[11] In the J. N. judgment,[12] the European Court of Justice (ECJ) ruled for the first time on the interpretation of the Reception Conditions Directive (RCD)[13] in relation to detention. In this judgment, the Court stated that: “detention is to be used only as a last resort, when it is determined to be necessary, reasonable and proportionate to a legitimate purpose.”[14] Every case needs to be assessed individually, and detention only considered if other less coercive alternative measures cannot be applied effectively.[15] Alternative measures to detention can, according to Greek law for example, include regular appearance before the authorities, the deposit of an appropriate financial guarantee, or the obligation to reside in a certain geographic area.[16] However, despite obligation by law, the application of alternative measures in Greece are neither examined nor applied in practice.[17] According to the European framework and to Greek law, asylum seekers cannot be detained “for the sole reason that he or she is an applicant for international protection or that he or she has entered the country illegally and/or stays in the country without proper documentation.”[18] 10