basis of the obstacles to return depends largely on the extent of the cooperation of the person concerned.73 Thus, it is possible that the new application is also rejected and the person remains in Sweden for years, pending implementation of the return decision. Some of these “unreturnable” individuals could be stateless, and statelessness could be the reason for their inability to return to their country of former habitual residence. The term “unreturnable” is used in this study to encompass persons who have not been granted leave to remain in Sweden, yet could not return or be returned to any country including, if known, their country of former habitual residence. This working definition was chosen to reflect the common characteristics that the group shares, in that they do not have the right to remain in Sweden while being unable to gain admittance to their country of citizenship or former habitual residence.74 The reasons for these persons’ precarious situation are often not known. It could be that they lack citizenship or a right to reside in the State to which they are to be deported, or that their State of citizenship refuses to readmit some of its citizens. This group falls within UNHCR’s mandate relating to stateless persons because prolonged situations of “un-returnability” may be an indication that the person concerned is stateless, or may eventually lead to statelessness.75 Due to the absence in Sweden of a mechanism or procedure for determining if a person is stateless, it is not possible to say with certainty how many of the “unreturnable” rejected asylum-seekers, or irregular migrants, meet the international law definition of a stateless person. 2.3 Qualitative analysis of stateless persons 2.3.1 Introduction While UNHCR would have liked to conduct participatory assessments76 with stateless persons living in Sweden to enhance its understanding of the background and situation of this population, it was not possible within the scope of this research project. This was partly due to the fact that the stateless population in Sweden can neither be easily identified as a group, nor can their contact details be readily obtained in order to call individual stateless persons for interviews or focus group discussions, using UNHCR’s participatory assessment methodology. Instead, a number of NGOs working with asylum, immigration and human rights issues in Sweden, such as Amnesty International, the Swedish Refugee Advice Centre and a couple of church organizations, were contacted by the consultant, and asked to share their experiences from counselling or otherwise supporting stateless persons in Sweden. From the responses given by these NGOs to the consultant’s questionnaire, and in follow-up meetings, it became clear that there is generally little awareness about the problem of statelessness and that the NGOs active in the aforementioned areas have not taken note of statelessness as an issue that may be affecting the situation of a client. There appears to be a similar lack of awareness 73 In two decisions by the Migration Appeal Court, MIG 2007: 46 and MIG 2009: 13, it has been emphasized that it is in the first place the responsibility of the applicant, subsequent to a return decision, to leave the country, rather than the responsibility of the Swedish authorities to implement the return by force. The burden of proof rests on the applicant to prove that the return has not happened without a fault of hers or his. Furthermore, the responsibility to contribute to the implementation of the return requires the applicant not to remain passive with regard to the implementation of the return, in addition to the requirement that the applicant does not hide or otherwise avoid contact with the authorities. 74 This term was suggested by the authors of the UNHCR and Asylum Aid study Mapping Statelessness in The United Kingdom, 22 November 2011, available at: http://www.refworld.org/docid/4ecb6a192.html. 75 UNHCR, Prato Conclusions, p. 8. 76 UNHCR, UNHCR Tool for Participatory Assessment in Operations, May 2006, First edition, available at: http://www.refworld.org/docid/462df4232.html. UNHCR STOCKHOLM, 2016 25