The author explores the concepts of socially sustainable development and participatory governance, from a legal and empirical viewpoint. He argues that participation of various stakeholders - including civil society - in participatory governance structures, is seen as the primary means through which to address the intrinsic tension between the imperatives of economic accumulation and those of sustainability and equity, embedded in the notion of socially sustainable development. He highlights the emergence of a "participatory governance entitlement" which draws on existing human rights law and the widespread recent practice of states and international organizations in this field. However, this entitlement is not sufficient to ensure a genuine voice for civil society (representing the marginalized) within participatory structures, as long as such structures are not geared with minimum safeguards to ensure authentic deliberation. The author proposed specific sageguards to strengthen the authenticity of participatory governance structures and avoid ther risks of co-option of civil society