The term of office is recognised as the foundation for the functioning of public authorities in a democratic state. The term of office is a universal legal structure, known to most political systems in the world. The content of the term of office consists of two basic elements: the temporal one, determining the maximum period of performing a public function by a supervisor or a member of the body, and the stabilising one, ensuring the minimal durability of personnel during the tenure. Due to the guaranteeing nature of the term of office, it is therefore necessary that any potential curtailment of the full tenure must be based on a clear legal permission, as well as should be exceptional and justified in the light of constitutional principles, norms and values. Each case of shortening of the term of office by means of an act of parliament (which has recently been the case in Poland) undermines social trust in public authorities and constitutes mostly an infringement of the constitution.