(4) In case of international crisis, or of real threats to the vital interests of all or part of the population or of imminent danger resulting from grave infringement of public security, the Grand Duke, after having declared urgency resulting from the impossibility of the Chamber of Deputies to legislate in the appropriate time periods, may take regulatory measures in all matters.
These measures may derogate from existing laws. They must be necessary, appropriate and proportionate to the goal pursued and be in conformity with the Constitution and with the international treaties.
... (Art. 32)