to this group, such as police stations, prisons, disused army barracks, hotels, mobile containers, etc., are also being used in order to detain growing numbers of persons. 3. Whilst it is universally accepted that detention must be used only as a last resort, it is increasingly used as a first response and also as a deterrent. This results in mass and needless detention. The Parliamentary Assembly is concerned by this excessive use of detention and the long list of serious problems which arise as a result and which are regularly highlighted, not only by Council of Europe human rights monitoring bodies such as the European Court of Human Rights, the European Committee for the Prevention of Torture and Inhuman or Degrading Treatment or Punishment (CPT), the Human Rights Commissioner and the Assembly’s Committee on Migration, Refugees and Population, but also by other international and national organizations. 4. Conditions and safeguards afforded to immigration detainees who have committed no crime are often worse than those of criminal detainees. Conditions can be appalling (dirty, unsanitary, lack of beds, clothing and food, lack of sufficient health care, etc.) and the detention regime is often inappropriate or almost entirely absent (activities, education, access to the outside and fresh air). Furthermore, provision for the needs of vulnerable persons is often insufficient and allegations of ill-treatment, violence and abuse by officials persist. This all has a negative impact on the mental and physical well-being of persons detained both during and after detention. 5. Detention is costly in financial terms for the states which often resort to this measure and which detain persons for lengthy periods of time. The European Union Return Directive, which provides for a maximum length of detention for irregular migrants of up to eighteen months, can be criticized for adopting the lowest common standard with regard to length of detention thereby 50