This PhD thesis examines the role of informal cooperation mechanisms in the development of normativity on labour migration. At its genesis lays a paradox: states would benefit from an effective legal regime on labour migration, which requires a strong commitment to international cooperation; however, they are reluctant to cooperate towards such regime as it impinges on their sovereignty. Consequently, cooperation on labour migration often takes place within political rather than legal frameworks. By identifying the shortcomings of international law in effectively regulating labour migration, this thesis searches for viable alternatives in shaping national legal orders on the topic. In doing so, it reflects on the role of inter-state consultation mechanisms in creating norms on labour migration through norm diffusion, walking a methodological path at the borderline between law and international relations. Through an in-depth analysis of the Colombo Process, one of the most active inter-state consultation mechanisms in Asia, and its participation in the drafting and implementation of the Global Compact on Migration, the thesis illustrates how specific standards of behaviour are diffused through informal dialogue mechanisms. Simultaneously, it highlights the characteristics of labour migration in Asia, the importance of its intra-regional dimension and the perspective of countries of origin, which are topics often forgotten in literature. This thesis provides arguments for a shift in advocacy efforts towards informal cooperation mechanisms, since they are able to create – through diffusion – new norms to the benefit of labour migration’s stakeholders, particularly migrant workers, while improving the overall international regime on labour migration.