Manuel Müller Making the Most of Transnational Lists Electoral Equality at EU Level Through Proportional Compensation INTRODUCTION The introduction of transnational lists is one of the most prominent approaches for a reform of the European elec­toral law(see Verger 2018, Diaz Crego 2021, with many oth­er examples). The proposal goes back to the 1990s and was discussed several times in the European Parliament(EP), in par­ticular in the debate on the so-called Duff Report(Duff 2012). In the context of the United Kingdom’s exit from the EU, the idea was raised again by French President Emmanuel Macron (2017) and supported by several other member states’ govern­ments. Various options are being discussed for certain design aspects – for example regarding the size of the transnational seat contingent, the use of preferential votes, etc.(Müller 2020, Diaz Crego 2021: 23–31). Although the proposal has so far failed to achieve the necessary majority in the EP and una­nimity in the Council, the political debate around it remains lively. Currently, transnational lists are one of the ideas that have received most endorsements on the digital platform of the Conference on the Future of Europe(Kantar Public 2021: 62) and play a central role in the Draft Report on electoral re­form that is currently discussed in the EP(Ruiz Devesa 2021). A variety of advantages are expected from transnational lists(Müller 2021, Diaz Crego 2021: 4–5 with more references). In the first place, they would strengthen the European political parties, increasing their political power and relevance through the right to draw up electoral lists. This increased role of the Eu­ropean political parties in the electoral campaign would also give visibility to their transnational platforms and foster transna­tional opinion-formation in the public sphere. Finally, transna­tional lists would strengthen the leading-candidates(Spitzen­kandidaten) procedure and thus increase the influence of Euro­pean voters on the appointment of the EU Commission. There is, however, an even more fundamental benefit of transna­tional lists concerning the formal legitimacy of the EP – more specifically, the question of transnational electoral equality. Un­der the current system, the EP is elected in national constituen­cies with separate seat contingents, whose size is»degressively proportional« to the number of inhabitants. As a consequence, larger member states elect fewer MEPs per inhabitant than smaller member states. While there are good reasons for this de­gressive proportionality – in particular, to guarantee an adequate representation of the party systems of the smaller member states in the EP –, the fact that votes cast in large member states have a lower success value is a serious breach of the principle of elec­toral equality and impairs the legitimacy of the EP as a democrat­ic representative body. As will be shown in more detail below, this is not only a political, but also a constitutional problem and a legal obstacle to a further institutional deepening of the EU. With the introduction of transnational lists, the principle of»one person, one vote« would be applied for the first time at a transnational level. However, the scope of its ef­fect on electoral equality would strongly depend on how trans­national lists are designed and implemented. The currently dis­cussed models usually envisage the introduction of an addi­tional EU-wide constituency that would be entirely separate from the national seat contingents. With such a model, the ef-