EU Enlargement and EP Seat Allocation Reform

Theses of the political initiative for the Policy Competition: EU Enlargement Reform of the seat allocation system in the European Parliament

by Anna Yemchuk and Karina Nesteruk

In the near future, several frontrunners for EU accession have emerged, namely Montenegro, Ukraine, Albania, and Moldova. The process of these states joining the EU highlights the urgent need for a fundamental reform of the representation system within European institutions. Unlike the European Commission, which operates on the clear principle of "one state, one commissioner" (currently 27 members), or the Council of the EU, composed of sectoral ministers from each member state, the structure of the European Parliament requires a more complex transformation.

Special attention must be paid to reviewing the mechanisms for forming the European Parliament ahead of the 2029 elections. Given the potential expansion of the Union, adhering to the established limit of 750 mandates will require a revision of the principle of "degressive proportionality." This creates potential political tension, as preserving the influence of founding states conflicts with the necessity of providing a fair representative quota to new member states without increasing the Parliament’s total headcount.

The issue becomes particularly acute when analyzing the potential membership of large states. Specifically, under the current allocation methodology, Ukraine could claim approximately 50 parliamentary mandates upon joining the EU. Such a significant share of representation may be perceived by other member states as a factor disrupting the political balance and national interests.

In light of this, we have developed a formula designed to balance the seat allocation system. The proposed model is based on the integration of two key indicators:

The implementation of such a methodology would ensure a transparent and mathematically grounded distribution of influence, minimizing subjective political disputes between new and old EU members.

The formula we propose for calculating the seats of states in the European Parliament is as follows:

186 seats – base, each state unconditionally receives 6 mandates; 423 seats – mandates depending on the population size;

141 seats – mandates depending on GDP per capita.

For visualization, we offer an approximate calculation of seats for the 2029 elections, taking into account demographic and economic data as of 2025-2026:

Thus, by changing the system of calculating mandates in the European Parliament before the next EU enlargement, it is possible to equalize political influence between states and achieve a compromise.

Despite the fact that traditionally seats in the EP are distributed only by population, enlargement, and especially the accession of such a giant as Ukraine, creates a situation where a large but economically weak state could obtain huge influence over the Union's budgetary decisions. According to our formula, Ukraine receives ~35 seats, and Poland ~41. This makes them a powerful bloc but does not allow them to outweigh the influence of traditional leaders (Germany and France). If after the future enlargement we calculated quotas only by population, Ukraine would claim a significantly larger number of quotas, which could cause resistance from Paris or Berlin. Our model offers an ideal balance, which requires the political will of states to sacrifice a small number of mandates, but at the same time is objective and relies on specific indicators.

Why should GDP per capita necessarily be taken into account in future reforms of influence distribution in the EU? Because it allows considering the economic contribution and level of development and reassures the "old" EU members (Germany, the Netherlands, Luxembourg), showing that their economic weight converts into political influence, and at the same time stimulates candidate countries to economic reforms in order to increase their quota in the future.

Besides this, keeping the total number of deputies within 750 is critical in our opinion, as this is the maximum permissible number under the Lisbon Treaty. Our model proves that even with the addition of 4 new countries (including large Ukraine), the system does not collapse and does not require inflating the staff to a thousand deputies, which would make the parliament unmanageable.

Therefore, we consider our initiative worthy of presentation at the competition, as well as for the application of at least certain aspects of it in the further policy of the European Union.