So who is building sustainable development? Transforming exploitative labour along southern corridors of migration There has been a 40% increase in the number of international migrants in less than two decades with 245 million international migrants on the move worldwide.  The majority have their trajectory restricted within countries in the Global South. Increased border limitations into the Global North mean that the promise of humanitarian protection and assistance is also falling disproportionately on the stronger of the southern hemispheric countries that as yet have not the structures in place to respond to new arrivals.  Simultaneously, public and private growth initiatives in the latter countries hinge on the availability of flexible labour for large, infrastructure projects  The Brazilian Amazon region is a key example of an emergent migrant destination.  Brazil's impressive economic performance in the first decade of the 21st century has been accompanied by a positive rhetoric towards immigrants and the rapid expansion of the local labour market.  Subsequent movement across the vast border that straddles seven countries and eight Brazilian states has been constituted not just by more conventional Bolivian, Colombian, Paraguayan and Peruvian migrants, but large numbers of recent Venezuelan arrivals, Haitian, Senegalese and Congolese migrants who have arrived in Brazil following rejection from northern borders.  They all try to make a living that is so far characterised by precarious status and resources so far. Hence new zones of humanitarian crisis are emerging throughout the rural and urban landscapes, and becoming so far poorly understood corridors of weakly regulated labour recruitment.  Through these corridors, informal and formal relations and contracts are channelled and combined, and lead to a critical deficit in so-called decent work in the very sectors on which the 'building' of sustainable economies depends. The key to sustainable development as defined by the ILO is thus not fitting at all.  This research explores increasingly dominant forms of employment regimes in the Global South where conventional distinctions between formal and informal work are over determined by local power relations. These relations are expressed in sectoral peculiarities for rapidly expanding infrastructure projects, and in the specificity of each individual's biographical trajectory.  In key sectors of construction, energy and agroindustry, these new regimes depend upon, while sustaining, demand for flexible labour. Conventionally sourced from domestic migrant labour it is increasingly being recruited from the Amazonian frontier between Bolivia, Colombia, Peru, Venezuela and the receiving country, Brazil.  An interdisciplinary research team will use a participatory and transformative research agenda that aims to investigate: (i) how a deficit in regulation and enforcement between formal and informal actors is turning humanitarian corridors into zones of social crisis for migrants seeking employment; (ii) to what extent the experience of exploitative work and labour analogous to slavery (work endured under threat of penalty, is forced, trafficked or involuntarily indebted) is a product of a series of informal and formal contracts along the migrant journey from home to workplace, (ii) how migrant workers, through collective and active knowledge building, can transform inequitable power relations across a range of spatial and hierarchical nodes.  The project seeks to understand the critical deficit in decent work from the perspective of those vulnerable workers most affected by current power inequalities across formal and informal recruitment and employment regimes to  inform participatory intervention at a key juncture in Brazil's economic and social development. These migrants will be integral to the global workforce of 2030, particularly in emerging economies, yet in 2018 they remain peripheral to how this is discussed. This proposal take a significant step towards engaging peripheral migrant workers in transforming this reality. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.