November 9, 2023

The Impact of Ukrainian Membership on the EU’s Institutions and Internal Balance of Power

European Union
European Council VTC with the President of Ukraine in Brussels, Belgium, on 26 October 2023.
European Council VTC with the President of Ukraine in Brussels, Belgium, on 26 October 2023.

While each previous addition of new member states has had an effect on the EU’s institutional architecture, the impact of Ukraine’s accession would be particularly large given the sheer size of the country.

In terms of pre-war population, Ukraine would be the fifth largest in the Union, amassing a vote share of almost 10% in Council decision-making passed by qualified majority. The addition of Ukraine’s veto right on matters decided by unanimity, its Commissioner, judge, and auditor would not, in and of themselves, render the institutions to which they pertain dysfunctional. But as more new members are added to the EU, the risk of complicating the smooth functioning of institutions goes up. The proportional allocation of seats to Ukraine would lead to the European Parliament (EP) exceeding its formal limit, thus triggering either treaty change or a proportional reduction of the number of seats for Members of the European Parliament (MEPs) from other EU countries. The EU’s internal balance of power would shift, not necessarily along geographical lines between East and West, as is commonly perceived, but more likely on policy issues that touch on Ukraine’s staunchly defended sovereignty. To stave off the risks inherent in the enlargement of the EU with Ukraine, as indeed Moldova and Western Balkan countries, member states have started exploratory talks about institutional reform. But any expectations about ambitious reforms should be tempered. Apart from the activation of Treaty-based mechanisms to facilitate decision-making and the introduction of what is legally required in terms of representational rights to incorporate Ukraine and other acceding countries, the political landscape is currently too divided for bolder EU institutional reform. Yet, without progress in political integration, the European Union would be destined to be reduced to an arena for contentious bargaining over national interests. Hence, this policy paper presents a number of recommendations.

Download and read: The Impact of Ukrainian Membership on the EU’s Institutions and Internal Balance of Power (PDF)


This paper is the second publication of the project on “The political and economic impact of Ukraine’s EU accession on the EU and Estonia” conducted by the ICDS in cooperation with the Centre for European Policy Studies in Brussels and the Ukrainian Institute for Economic Research and Policy. The multi-disciplinary research team assesses the potential political, security-related, institutional, economic, and budgetary implications of Ukraine’s EU accession. The project is led by Dr Kristi Raik, Deputy Director of the ICDS, and supported by the Estonian Ministry of Foreign Affairs.

Read also the first paper of the project here: The Potential Impact of Ukrainian Accession on the EU’s Budget – and the Importance of Control Valves (PDF)