In December 2017, the European Commission presented a communication on the creation of a European Minister of Economy and Finance, proposing to merge the functions of the European Commissioner in charge of economic and monetary policy with the position of the Eurogroup's President. This paper reviews the legal framework in which the European Finance Minister would operate and highlights the legal and institutional implications of the Commission's proposal. It analyses the potential impact of the new institutional arrangements on the Commission's collegial organization, on the inter-institutional balance of the Union and on the accountability relations between the Commission and the European Parliament. The paper ultimately questions the Commission's assumption that the proposed changes could be implemented without modifying the Treaties and raises some fundamental issues regarding the impact of the reform on the democratic legitimacy of the Union in the absence of Treaty revision.