Abstracts. The article provides a comprehensive analysis of the functioning mechanism of the constitutional legal order under martial law, in particular the means and methods by which it can protect constitutional values, rights and identity from internal and external threats, and also offers practical recommendations for preventing the possible involution of constitutionalism in the post-war period. The author believes that after the large-scale invasion of the Russian Federation on the territory of Ukraine, the practical paradigm of Ukrainian constitutionalism acquired new features. First, it is a change in the ideological component of the content of constitutionalism - constitutional legal awareness in the direction of raising the national idea, national identity, and affirming the national dignity of Ukrainians. At the same time, it is based on the European model of constitutionalism, which corresponds to universal human values, first of all, human dignity and freedom, which are unchanged even under martial law. Secondly, these are changes in the functional mechanism of constitutionalism, which are caused by the need for public authorities to ensure a balance between the security and freedom of citizens with the unwavering observance of fundamental human rights and freedoms, which cannot be limited even in war. Thirdly, the formation of a new identity around the new (post-war) constitution, which should become an expression of the hope of the entire Ukrainian people for their dignified political and socio-economic future in a united Europe. The author of the article claims that the war in Ukraine has a pronounced existential character, as it directly affects the choice of the future of every Ukrainian and the Ukrainian political nation in general. In this war, Ukrainians defend not only their right to exist as a separate ethnic group, but also universal, European values, which are reflected in the Constitution of Ukraine - above all, the idea of freedom and democracy. The European choice of the Ukrainian people is the result of the Orange Revolution and the Revolution of Dignity. This choice remained unchanged even during the war. In the conditions of war, the legitimacy of the use of extraordinary measures by state authorities lies in two areas: first, such measures must be urgent and eliminate the threat to the constitutional order, in particular, the viability of the nation in the event of external aggression; second, accountability and control of the government, which includes parliamentary and judicial control. In such a situation, the institutional capacity of the state to ensure human rights and freedoms is important. A special role is assigned to the judiciary, which must ensure the inalienable, inalienable right of a person to free access to justice. The article focuses attention on the importance of the Constitutional Court of Ukraine, local self-government bodies and institutions of civil society in ensuring human rights in extraordinary conditions. Attention is also drawn to the fact that the formation of the Ukrainian political nation in the post-war period should take place around the new constitution. It should become a real social contract of the Ukrainian people - citizens of all nationalities who did not renounce their citizenship during the war and those who acquired it after the war through their will. The basis of this agreement should be the three defining values of constitutionalism - freedom and dignity of the individual, identity and dignity of the nation, supremacy of the constitution and norms of international law. They should find their reflection in the Preamble of the Constitution of Ukraine, which forms the basis of constitutional identity.