(Legal force) 1. The constitutional precepts with regard to rights, freedoms and guarantees are directly applicable and are binding on public and private entities. 2. The law may only restrict rights, freedoms and guarantees in cases expressly provided for in the Constitution, and such restrictions must be limited to those needed to safeguard other constitutionally protected rights and interests. 3. Laws that restrict rights, freedoms and guarantees must have a general and abstract nature and may not have a retroactive effect or reduce the extent or scope of the essential content of the constitutional precepts. Article 19 (Suspension of the exercise of rights) 1. Entities that exercise sovereignty may not jointly or separately suspend the exercise of the rights, freedoms and guarantees, save in the case of a state of siege or a state of emergency declared in the form provided for in the Constitution. 2. A state of siege or a state of emergency may only be declared in part or all of Portuguese territory in cases of actual or imminent aggression by foreign forces, a serious threat to or disturbance of democratic constitutional order, or public disaster. 3. A state of emergency is declared when the preconditions referred to in the previous paragraph are less serious, and may only cause the suspension of some of the rights, freedoms and guarantees that are capable of being suspended. 4. Both the choice between a state of siege and a state of emergency and the declaration and implementation thereof must respect the principle of proportionality and limit themselves, particularly as regards their extent and duration and the means employed, to that which is strictly necessary for the prompt restoration of constitutional normality. 5. Declarations of a state of siege or a state of emergency shall set out adequate grounds therefore and specify the rights, freedoms and guarantees whose exercise is to be suspended. Without prejudice to the possibility of renewals subject to the same limits, neither state may last for more than fifteen days, or, when it results from a declaration of war, for more than the duration laid down by law. 6. In no case may a declaration of a state of siege or a state of emergency affect the rights to life, personal integrity, personal identity, civil capacity and citizenship, the non-retroactivity of the criminal law, accused persons’ right to a defence, or the freedom of conscience and religion. 7. Declarations of a state of siege or a state of emergency may only alter constitutional normality in accordance with the provisions of the Constitution and the law. In particular, they may not affect the application of the constitutional rules concerning the competences and modus operandi of the entities that exercise sovereignty or of the self-government organs of the autonomous regions, or the rights and immunities of the respective officeholders. 8. Declarations of a state of siege or a state of emergency grant the public authorities the competence to take the steps that are necessary and appropriate for the prompt restoration of constitutional normality. Article 20 (Access to law and effective judicial protection)