Abstract: The Spanish constitution proclaims Spanish unity to be indissoluble and, therefore, does not recognize the right to secession. However, this prevision could be reformed, even if it involves rather complicated processes. All said, it is good to bear in mind that different internal and international jurisdictions have recognized that national communities have a right to decide their political future collectively; including secession, understood to be a political aspiration, protected by the democratic principle of freedom of speech, and the right to participate can direct the modification of the constitutional order of a state, in a way that is legal and agreeable to all involved. However, there are cases of national communities that do not recognise that right, or the parent nation shows no desire to negotiate the terms of an improved accommodation of their political status, or allow a referendum to be held for this effect. In these cases, the recent practice of some States as well as comparative law, show the viability, under certain conditions, of a unilateral declaration of independence. Enllaç a l’article sencer