This article examines the consequence of treating irregular labour migration as a criminal law issue, rather than one of trade or development. If States are increasingly committed to the free movement of goods and skilled workers, why is the movement of unskilled workers a crime? Adopting an economic analysis, it is clear that irregular migrants provide labour-receiving States with a pool of workers who are cheap to employ, easy to fire, and who are effectively unable or unwilling to invoke employment rights. That is, migrant workers can be a significant source of cheap and rightless labour. Furthermore, this may be viewed not as a market distortion but a highly regulated part of the ordinary functioning of destination economies. The economic benefits of irregular migrants result from their status: a status regulated and perpetuated by law. High- and medium-income States may become structurally dependent upon this externalized «ghetto» of low-cost foreign labour, thus profiting from irregular migration while denouncing it. This article argues that, if irregular migration economically benefits destination States and is driven both by lack of development in labour-sending States and migrants’ opportunity to remit money home, then the answer must lie in expanded systems of «regular» labour migration closely linked to development policy. Policy approaches must consider not only a trade/migrant – labour nexus but a trade/migrant – labour/development nexus. The article concludes by advocating that a set of principles of sustainable return is in the self-interest of labour-receiving States and outlining the content and utility of such principles. While the article aims to provide a theoretical account in an outline form that is adaptable to a variety of situations, it uses the example of African irregular migration into Spain and Spanish/EU responses to illustrate the argument.