How the European Parliament Has More Ways to Leverage Its Power Than You Might Think in EU Enlargement Policy

This blogpost is based on the article Jansen, L., Paulissen, T. & Van Hecke, S. “Power Beyond Borders? Analysing Formal and Informal Tools of the European Parliament in EU Enlargement Policy” published in Journal of Contemporary European Studies (https://doi.org/10.1080/14782804.2024.2448257) and the related UACES Graduate Forum Blog Post.

In the wake of Russia’s full-scale invasion in 2022, the topic of EU enlargement has once again taken centre stage, breaking through more than a decade of ‘enlargement fatigue’ that followed Croatia’s accession in 201.. Fuelled by a renewed sense of geopolitical urgency, not only countries within Russia’s direct orbit (i.e. Ukraine, Moldova and Georgia) but also several Western Balkan countries have made significant progress in their membership trajectories since February 24 2022. In the context of EU enlargement, the European Parliament (EP) plays a crucial yet often underestimated role. Traditionally, the European Commission and the European Council have been the primary actors in this policy domain. However, the EP’s potential to contribute to the debate extends far beyond a simple procedural step in the accession process. The EP’s role in EU enlargement is anchored in both formal powers granted by EU treaties and other (legal) texts, alongside a range of informal powers that have emerged as part of its ‘self-empowerment strategy’ developed over time. In their article "Power beyond borders? Analysing formal and informal tools of the European Parliament in EU enlargement policy," Lien Jansen, Toine Paulissen and Steven Van Hecke (2025) offer a comprehensive examination of five key tools through which the Parliament can leverage its influence over the enlargement process: the consent procedure, budgetary authority, agenda-setting, parliamentary oversight and standing parliamentary delegations.

Among the five identified tools, the consent procedure and the power of the purse stand out as the most prominent. Indeed, one of the European Parliament’s most straightforward tools to weigh on enlargement policy is the consent procedure. Under this legislative procedure, the Council is obliged to consult the Commission and secure the Parliament's consent before moving forward with any membership application. This effectively grants the European Parliament veto power, enabling it to either approve or block a candidate's accession to the EU. However, this veto power is considered to be a rather ‘blunt tool’ as it offers legislation to the EP on a ‘take-it or leave-it basis’, leaving no room to bargain, let alone amend the final text of the accession agreement. Nevertheless, the European Parliament has developed informal practices that help mitigate the formal constraints of the consent procedure. To ensure its concerns are taken into account during the accession negotiations, the EP can, - for instance - adopt resolutions outlining conditions for consent or resort to its power of delay regarding international agreements.

Similarly, the EP’s involvement in the Multiannual Financial Framework (MFF) and the Annual Budget allows it to link funding to specific conditions related to enlargement. Concerning the MFF, the Treaties require the EP to give consent by absolute majority before the Council can adopt the MFF. Additionally, sectoral regulations, which provide the basis for the funding of almost 40 EU spending programs over a seven-year period, are agreed upon under the Ordinary Legislative Procedure putting the EP on equal footing with the Council. This effectively makes the EP a co-legislator on the main external financing instruments regarding enlargement (i.e. IPA and NDICI) as the ceilings and overall amounts of these instruments are decided by the MFF, but not exactly how they are organised, i.e., their general and specific objectives and the size, form and rules of the funding.

It is, however, within the seven-year ceilings of the MFF that the Parliament’s power is most prominent, as it needs to agree with the Council on the Annual Budgets following a special legislative procedure. The Annual Budget is often identified as a very important tool that offers indirect leverage in the area of foreign policy and enlargement and allows the Parliament to steer the political direction of these policy domains. Nevertheless, this power remains at all times constrained by the limited room for manoeuvre left by the MFF. Several scholars (f.e. Corbett et al. 2016; Lord (2017) therefore emphasize that one of the best strategies for the EP to still maximize its (potential for) influence, is aiming at a limited number of priorities in successive annual budgets. However, this strategy is highly dependent on internal cohesion, as conflict seems almost inevitable on a sensitive subject such as the budget, which basically covers all policy areas.

Another key tool concerns the Parliament's agenda-setting power. Through resolutions, (own-initiative) reports, speeches by the EP president and parliamentary debates, the European Parliament can elevate the prominence of EU enlargement, ensuring its remains central to the EU policymaking. At the same time, these instruments enable the EP to bring neglected aspects of the accession process to the forefront. As the public face of the Parliament, the President plays a crucial role in determining whether and how an issue is incorporated into its public messaging. For instance, the current President, Roberta Metsola, frequently underscores the geopolitical necessity of enlargement in her speeches, as illustrated by her recent address at the EU Ambassadors Conference 2025 (analysed using Prismos' chat function). Additionally, the European Parliament plays a crucial role in overseeing the executive, primarily the Commission by scrutinizing enlargement policies through powers as the appointment of the Commissioner for Enlargement (see Prismos’ analysis on the November 2024 hearing of the current enlargement commissioner Marta Kos), debates on statements of the Commission and/or Council, parliamentary questions, information and consultation rights in Association and Accession agreements and, finally, budgetary scrutiny via the discharge procedure. The final key tool is the EP’s network of standing parliamentary delegations to (potential) candidate countries. These delegation serves as an important channel for information exchange and political dialogue, enabling MEPs to gather essential knowledge, which in turn facilitates well-informed decision-making. Additionally, they function as ‘preparatory agents’, laying the groundwork for executive decisions, as they have more space to manoeuvre compared to traditional diplomacy (see for instance Prismos' analysis of the recent EU-Serbia SAPC meeting, particularly in the context of the massive student protests that have erupted across the country)

Despite the EP’s broad range of instruments, the EP’s role in enlargement is not without its limitations. In addition to its relatively limited formal powers, a majority among its members - obviously - appears to be crucial, particularly in the consent and budget procedures. Hence, conflicting interests and political divisions can weaken the Parliament’s bargaining position. Moreover, the overlapping competences between the committees and the standing parliamentary delegations, coupled with the volunteerism in delegation appointments, challenge the effectiveness of these inter-parliamentary bodies. Lastly, the timely and complete information-sharing by the Commission and Council is crucial for the EP’s ability to conduct effective parliamentary oversight in EU enlargement policies (and beyond). Taking these caveats into account, it becomes clear that the European Parliament possesses a range of (in)formal tools to weigh on the accession process. While much depends on the willingness of intra-and inter-institutional political actors to do so, it is an institution that should not be overlooked, especially in the wake of Russia's full-scale invasion and the renewed sense of urgency regarding EU enlargement.

Lien Jansen is a Research Foundation Flanders (FWO) PhD Fellow for Fundamental Research at the KU Leuven Public Governance Institute. Her research focuses on European Politics with a special focus on the European Parliament and EU enlargement towards the Western Balkan countries.

Contact: lien.jansen@kuleuven.be