This paper analyses the role of third parties in the enforcement of the Foreign Subsidy Regulation (FSR). It focuses on competitors, customers, and suppliers – market participants directly affected by distortive foreign subsidies – as a special form of third parties.Third parties might have a vested interest in the enforcement of FSR against subsidy beneficiaries because they might be affected by the distortive effects of foreign subsidies. The subsidy might put the beneficiary undertaking in a more favorable financial position than undertakings that do not receive such subsidies. While the primary goal of the FSR is to protect the internal market as a whole, its structure and efficiency rather than protecting some of its actors, the potentially harmful effects of foreign subsidies on third parties should not be disregarded and warrant an involvement of third parties to prevent or redress the harmful effects of subsidies.Third parties could also aid the Commission in enforcing the FSR, which ultimately leads to an overall more effective enforcement of the FSR. By participating on the same or adjacent markets as the subsidy beneficiaries, competitors, in particular, could, e.g., bring the existence of a third country subsidies to the awareness of the Commission, help determine which undertakings are in a comparable legal and factual situation to establish a selective benefit in the view of Article 3(1) FSR, aid to assess the likely effects of a measure on the market or the usability and effectiveness of redressive measures. Lastly, similar to competition and state aid law, third parties could remedy the institutional deficit and limited administrative capacity due to considerable budgetary and human resources constraints on the part of the Commission and act as “private attorney generals” to vindicate their own rights through measures of private enforcement, at the same time ensuring the compatibility with the FSR.Consequently, the paper investigates complaints, participation in Commission FSR proceedings, judicial review, and private enforcement in national courts. It draws some conclusions and comparisons with third party enforcement in other areas of EU law, notably EU State aid, competition, merger control, and trade law, but it works out the unique approach for third party enforcement of the FSR. Despite the FSR's gap-filling function, it deviates significantly from third party enforcement in other areas of EU law, as it only provides limited options for such third-party enforcement
