This article defends the case for a global extension of democracy by deploying a cosmo-federalist theory. As a response to the current state of international exclusion, the radical project of stretching the paradigm of democratic inclusion to the extreme limits encompassing the whole of mankind, is here presented. The article begins by taking position for a choice-based version of consequentialism that generates a principle of political justice centred on political participation. From this, a political project is developed that envisages a cosmopolitan system where all world citizens are included within a scheme of a direct representative participation under an overarching authority governing the process of democratising world affairs. Crucial in this is the establishment of an all-inclusive authority to legitimately delineate jurisdictional boundaries and a multilayered system of political interaction.