There is currently no dispute that the legislative body can perform certain activities beyond the legislative function, which fall within the scope of the administrative function. However, there are several legal areas that are not clear as to which acts of the legislature fall within the scope of the administrative function and whether judicial remedies can be taken against them, and if so, to which judicial body it is possible to apply. One such ambiguous area is the legal nature of the disciplinary penalties imposed on members of parliament and the judicial body to which they can be appealed. The present study aims to discuss this issue within the framework of scientific jurisprudence and judicial precedents. The issue is analyzed within the framework of the substantive (functional) and formal (organic) criteria employed in the classification of state functions and the concept of the administrative act. From our standpoint, disciplinary penalties imposed on members of parliament by the legislature do not fall within the scope of the legislative function, but within the scope of the administrative function. Therefore, we believe that disciplinary penalties imposed on MPs must be subject to administrative judicial proceedings.