ABSTRACT
Any system of allocating seats in the European Parliament should obey the principle of 'degressive proportionality'. Although this principle can be made mathematically rigorous, it does not lead to a unique solution. Hence, it is possible to construct several different allocation systems which satisfy all required constitutional constraints. Theoretic analysis does not allow one to distinguish an optimal system of allocation of the seats in the European Parliament. The Penrose square-root system, optimal in the case of the European Council, is not distinguished by any arguments in the case of the Parliament. The reason is that the representative of each state cannot split his vote in the Council, while members of the Parliament from a single country may vote differently to represent the opinion of their electors. From the mathematical point of view one may distinguish regular methods of allocating seats in the European Parliament which realise the principle of degressive proportionality.
