Refugee Survey Quarterly  55 the challenges and ethical dilemmas working in immigration detention felt affected by the injustice of the system, which in several cases was considered to be constructed so as to deliberately undermine migrants’ human dignity and de-legitimise not only immigration but also the persons who have travelled irregularly. The supporters of this position argued that limiting MSF’s criticism on detention conditions, and arguing for amelioration rather than questioning the very existence of the detention system, could be interpreted as indirectly supporting this highly harmful set of policies. The difference of opinions within MSF demonstrates that the perception of humanitarian principles within an organisation is not only influenced by the organisation’s values and culture but also by the individual sense of moral responsibility. It also highlights the tension between “traditional” humanitarian principles and a more rights-based approach. Some MSF workers felt a greater sense of moral responsibility to speak out, because advocacy was targeted towards their so-called “home” societies in Europe. Others were motivated by their daily contact with migrants in detention. The debate also reflected a difference of opinions about the very decision to intervene in immigration detention settings, which ran through the organisation: those in support of intervening considered the restoration of detained migrants’ dignity a valid objective alongside the “traditional” objectives of reducing morbidity and mortality, but others in the MSF movement have remained reluctant to invest in such projects, due to inherent operational constraints linked with working in an environment of incarceration and the difficulty of making an impact. 7. CONCLUSION MSF’s experience in Greek immigration detention centres demonstrates the challenges and dilemmas that an independent medical organisation is faced with when trying to help people who are suffering as a result of the deprivation of personal freedom and of their migratory status. These challenges and dilemmas relate to ensuring independent access to people in need, offering meaningful help while addressing health needs caused by incarceration, and working under the restrictions imposed by the detention authorities. Humanitarian organisations have a significant role to play in providing direct assistance in an independent and ethically acceptable way, and bearing witness to the suffering of these people by reporting on their findings and advocating for change. The experience of detention for migrants and refugees in contemporary Europe throws the possibilities and limitations of this vision into stark relief.