1 Reporting organisations Mobile Info Team (MIT) is a Greece-based organisation that provides advice and assistance throughout all stages of the asylum procedure. MIT raises awareness and advocates for changes to the asylum system in Greece, and works to end pushbacks as part of the Border Violence Monitoring Network. I Have Rights (IHR) is a non-profit law clinic that assists people undergoing the asylum procedure on the Greek Aegean island of Samos. IHR engages in advocacy and strategic litigation with an aim towards ending the detention of people on the move, ending the illegal practice of pushbacks, and defending the right to seek asylum. IHR is a member of the Border Violence Monitoring Network. Border Violence Monitoring Network (BVMN) is a coalition of organisations working to document illegal pushbacks and related violations along the EU’s external borders in the Western Balkans, Greece and Turkey. The collection of data on violations is done by a consortium of independent field experts who are part of or cooperate with partner organisations united through the Border Violence Monitoring Network. Executive summary In this submission we present key challenges and recommendations relating to formal immigration detention and de facto detention in Greece. We identify systemic challenges, as well as contextual differences, in the practices of both Pre-Removal Detention Centres (PRDCs) [1] on the Greek mainland and Closed Controlled Access Centres (CCACs) on the Aegean island of Samos [2]. The submission distinguishes formal immigration detention in the PRDCs and what we argue amounts to de facto detention in the CCACs, a form of detention which we note is absent from the General Assembly Resolution (A/RES/76/172) [3]. The Greek State imposes measures of containment that we affirm clearly contravene several aspects of the Resolution and amount to an unlawful deprivation of liberty and inhuman and degrading treatment in violation of ECHR Articles 3 and 5. Key challenges relating to immigration detention in Greece We assert that the Greek State’s immigration detention practices present key obstacles to the fulfilment of obligations outlined in the Resolution adopted by the General Assembly on 16 December 2021 (A/RES/76/172), which calls on States to put an end to the arbitrary arrest and detention of migrants, to pursue alternatives to detention while assessments of migration status are under way, to work towards ending the detention of migrant children, and to prosecute acts of violation of the human rights of migrants and their families [4]. We identify the following ongoing key challenges relating to immigration detention in Greece: Arbitrary apprehension and detention of asylum seekers and migrants in irregular situations Migrants and asylum seekers in Greece are routinely subjected to detention within PRDCs, police stations and other detention sites which is arbitrary both in terms of reason and length and represents a continued and widespread violation of their human rights, including through prolonged detention in police stations, and the excessive and disproportionate use of the maximum limit of administrative detention of 18 months, and in some cases 36 months, within PRDCs [5]. Migrants in irregular situations and asylum seekers are additionally frequently apprehended and detained by Greek authorities on the mainland without being provided with a