The subject of this article focuses on the protection of the public interest of member states in connection with the reporting of legal violations within the fundamental operational structures of the European Union. Its goal is to analyze the provisions of Directive (EU) 2019/1937 of the European Parliament and of the Council concerning the safeguarding of common interests in the areas of public procurement, financial services and markets, anti-money laundering and counter-terrorist financing, product safety, transport, environmental protection, public health, and personal data, as well as the financial interests of the Union. The article uses the dogmatic-legal method to interpret legal norms, including potential legal gaps and ambiguities that may pose a problem for the implementation of Union law into the legal systems of member states. Based on the provisions of this Directive on persons reporting legal violations and the views of legal scholars, the validity of the research theses presented in the introduction is also justified.