This article examines three specific examples of struggles waged by migrants who, through various forms of activism and mobilisation, and in collaboration with other collective actors, have called on the Spanish, French and United States governments to promulgate the unconditional regularisation of all persons currently suffering the condition of aliens as a result of these governments' policies. The migrant movements also demand social, economic and political rights for all citizens, irrespective of ethnicity, class and gender. The article looks at the migrants' movement in Barcelona, the Ninth Collective coordinating undocumented migrants ('sans papiers') in Paris, and the Movement for Justice in El Barrio, New York. This is a novel type of social movement, one that eludes formal structures of representation, such as are found in classic trade unionism, but which, we would argue, is, on account of its claims and activists, of key importance for anyone seeking to understand or promote workers' rights in contemporary urban settings.