This panel brings political scientists and legal scholars together to discuss problems of trust, accountability and fragmentation in the EU. Dermot Hodson and Imelda Maher explore changing approaches to EU treaty revision. The constrained role given to parliaments, courts and the people in treaty revision over the last two decades, they argue, reinforces problems of trust in national executives and wider concerns over two-level legitimacy. Deirdre Curtin looks at the changing governance of secrecy in the EU. National executives have traditionally exercised a high degree of discretion in areas such as diplomacy, security and defence and the provision of access to official information. This paper explores how debates over democratic checks on such discretion have an added layer of complexity at the EU level because of the fragmentation of executive power between national and supranational institutions and due to problems of trust in EU internal and external security policy. Kenneth Armstrong re-examines the UK’s relationship with the EU in the light of the 2014 referendum on Scottish independence. He revisits debates over how to deal with the UK’s fragmented membership of the EU in the event of a ‘yes’ vote and the question of whether a process of treaty revision or accession would have been triggered for an independent Scotland. Fernando Mendez examines the EU’s contradictory response to demands for direct citizen input to influence the direction and scope of European integration. He asks whether lessons can be drawn from other multi-level polities about how to work through these contradictions.