This article deals with the question of which state, in the case of overlapping jurisdictions, should investigate, prosecute and try offences in the European area of freedom, security and justice (choice of forum). As binding instruments on the choice of forum currently have no priority for the European legislator, this issue is de facto left largely to the legislative and executive branches of the Member States. Yet the question of whether this Member State discretion is acceptable de iure remains unanswered. This article assesses the relevant EU instruments in light of the requirement of a 'tribunal established by law' (Article 6 ECHR; Article 47 CFR) and addresses the issue of whether this requirement, in addition to its role in the national context, is also of relevance for the AFSJ as a whole. It is submitted that the choice of forum has a clear constitutional dimension, including a prominent role for the national and European judiciary as well. Only if concerns of losing national sovereignty are overcome will it be possible to start the debate on what actions must follow.