Composite Supervision and Constitutional Pluralism in European Media Governance: The Role of National Regulatory Authorities in a Polycentric Media Ecosystem

This paper examines the role of public authorities, particularly national supervisory and regulatory authorities (NRAs), in supporting and strengthening media pluralism within increasingly complex European media ecosystems. Media pluralism is approached as a constitutional value anchored in Article 2 of the Treaty on European Union, which identifies pluralism as a foundational value of the Union, and in Article 11 of the Charter of Fundamental Rights, which protects freedom of expression and information and explicitly recognises media pluralism. These constitutional commitments require public authorities to move beyond non interference and to actively shape regulatory environments capable of preserving diversity of voices, accessibility of information, and democratic resilience. Media ecosystems today encompass both legacy media sectors such as broadcasting and press, and new media environments dominated by platforms, algorithmic distribution, and data driven business models. Power that goes beyond traditional market power, including control over audience access and editorial visibility, reshapes how information is received by citizens, thereby creating new regulatory challenges for media pluralism. The paper situates the constitutional value of media pluralism and the right to information within the limits of Union competence in media matters. While the EU lacks an explicit competence to regulate media pluralism, internal market harmonisation has progressively expanded regulatory intervention in audiovisual and digital services. The Vivendi case (C-719/18) illustrates the intersection between freedom of expression, media pluralism, and market regulation, particularly in the telecommunications and media sectors. This competence configuration has produced a system of composite supervision, in which responsibility for safeguarding pluralism is distributed across national regulators, European coordination bodies, sector specific authorities, courts, and increasingly private actors through self and co regulatory mechanisms. Instruments such as the Audiovisual Media Services Directive, the European Media Freedom Act, the Digital Markets Act, the Digital Services Act, and the Political Advertising Regulation exemplify this layered governance structure, combining decentralised national enforcement with European level coordination. This composite architecture generates a polycentric supervisory environment marked by differentiated institutional capacities and complex accountability relationships. While the DMA centralises enforcement at EU level, the Audiovisual Media Services Directive, the European Media Freedom Act, the Political Advertising Act and, to a degree, the DSA rely on decentralised enforcement through NRAs and national Digital Services Coordinators. These authorities are expected to exercise their powers with independence, transparency, and accountability, while coordinating with European bodies and other national regulators. At the same time, self and co-regulation extend regulatory functions to private actors under structured conditions of oversight and transparency. The paper further addresses the heterogeneity of NRAs across Member States, reflecting diverse constitutional traditions, administrative structures, and media landscapes. While institutional diversity enables contextual adaptation, it also risks fragmented enforcement capacity and uneven protection of constitutional values. The paper argues that effective protection of media pluralism requires strengthened coordination mechanisms, procedural transparency, and clearly articulated interfaces between public regulation and private governance. Ultimately, NRAs must function as constitutionally grounded nodes within a multi level supervisory system capable of translating Articles 2 TEU and 11 CFR into operational regulatory practice.