Objective/Context: This text analyses the assembly debates that preceded the dissolution of the first Mexican Constituent Congress in 1822. The research focuses on the ideological context that gave rise to the idea of dissolution. It examines the language and arguments used to defend or question the continuity of the national representative body of the First Empire. Methodology: For this purpose, the minutes of the Congress will be studied from the end of August, when the “republican” conspiracies against the government of Agustín de Iturbide took place, until its dissolution at the end of October. Through dialogue with various contemporary publications, the proceedings will be contextualised within the currents of liberal thought that fed political debates at the time. Originality: In recent years, thanks to the celebration of the Bicentennial of Independence, historiography has developed research on the period of the First Mexican Empire. However, there is still a long way to go to understand how the theoretical foundations that articulated a constitutional monarchy as the first project of a nation-state in Mexico were forged. Through unpublished sources and a reflection in dialogue with recent historiographical contributions, this article deepens the analysis of the political thought that sought to imagine an empire based on the foundations of political liberalism at the beginning of the nineteenth century. Conclusion: The idea of dissolution, far from being a unilateral decision by Iturbide’s government, resulted from a dialogue between different factions and political interests. Its argumentation was always based on the new constitutional language.