Objectives:
The mechanism behind such complaints is intended to ensure an additional layer of security between the citizen and public institutions. The models established in European Union Member States show that the very concept of a constitutional complaint, as well as the formal requirements and its placement in the legal system are not uniform. Particular importance should be attributed to placement of this mechanism in the judicial system of an analysed country. In order to fully comprehend how effective the level of protection of rights truly is and what are the exact consequences of such regulations, it is imperative to determine whether the procedure is regulated in the constitution itself or through statutory law.

Material and methods:
In order to create this article general scientific research methods were used, both empirical and theoretical (analysis, synthesis, abstraction, generalization and induction). Systemic, functional and comparative research methods were also included.

Results:
The article presents various models of constitutional complaints with reference to their role in influencing the level of human and citizen rights and freedoms protection.

Conclusions:
Different levels of protection of human rights and freedoms are provided by European countries depending on the model of regulations they chose. From a legal and factual point of view, this lack of unison does raise legitimate doubts. However, the majority of EU member states are also signatories to various conventions and treaties concerning human rights and freedoms. In view of the above, the question of internationally standardising the scopes of complaints and procedures used by constitutional courts or tribunals, should be considered so that member states (at least during their EU membership) cannot restrict or violate any rights.