The principle of "one person, one vote" does apply - but only within the individual member states. On the other hand, the same applies to the whole of Europe: Larger countries have fewer MEPs per inhabitant than smaller ones. This "degressive proportionality" is intended to ensure that even the smallest countries with their party systems are adequately represented in Parliament.
However, it also leads to votes from smaller countries having a greater influence on the composition of the Parliament, thus distorting the balance of power between the EU groups. This is not only a problem for the formal democratic legitimacy of the EU. According to the Lisbon jurisprudence of the Federal Constitutional Court, it is also a constitutional obstacle to future deepening steps.
An EU electoral law reform should therefore achieve a double goal: preserve the degressive proportionality for the national seat quotas - but at the same time ensure that the balance of power between the political groups in the European Parliament corresponds to their voting ratio. The best solution for this is a proportional balance via pan-European lists: in this case, the "pan-European" seats would be distributed in such a way that, taking into account the national quotas, the total number of seats for each political group equals its EU-wide share of the vote.
In a policy paper commissioned by the Friedrich-Ebert-Stiftung, Dr. Manuel Müller has described how such an election procedure could look. With several examples of calculations, he describes how it would work and analyses challenges in its implementation.