The principle of subsidiarity is meant to demarcate the exercise of competences between the EU and its Member States and to balance the claim for regulatory power which these two legal worlds make. This article takes the view that subsidiarity has not proven so far to be a very useful touchstone in this regard. Moreover, there are still shortcomings in its envisaged application based on the legal framework provided by the Lisbon Treaty. It is therefore suggested that an approach beyond subsidiarity should be taken in future research in order to shed more light on how powers are balanced in practice in the EU. This approach submits for exploration the following hypothesis: the competences between the EU and its Member States are demarcated in daily practice by negotiating and balancing national discretionary powers, rather than defined through the legal framework and application of subsidiarity. In this view, two paths of research are proposed. The first identifies the Council, more specifically its de facto decision-making body, the Committee of Permanent Representatives (Coreper), as an arena for using Member States’ national discretionary powers in the process of negotiating legislation at the ex ante EU law-making level. The second view suggests an analysis of how the powers are balanced at the ex post law-making level by the European Court of Justice (ECJ) when assessing the principle of proportionality and thereof the margin of discretion left to the Member States in protecting their national powers and interests. These two specific perspectives are to be placed in the broader perspective of achieving national interests while still contributing to the unity of EU law-making.