The present essay analyses how in the current phase of "interregnum", in which conventional labour unions struggle to reach marginalised segments of the working class and to act effectively through traditional means of self-protection, new forms of collective organisation and action are developing within the social fabric to fill this gap. In particular, after outlining some theoretical considerations regarding the possibility of framing these phenomena within the scope of Articles 39 and 40 of the Italian Constitution, space is devoted to two case studies – the Collettivo di Fabbrica GKN and the Collettivo Autonomo Lavoratori Portuali – in order to assess the concrete impact that these new formations seem to have on both the material and legal realities.