Mathematically, the allocation of seats at the three levels works as follows:
1. Preliminary investigation (at regional constituency level)
First, the electoral quotient is determined for each province by dividing the total number of valid votes cast in the provincial constituency by the number of seats to be allocated in that constituency. The electoral quotient determined in this way (according to the so-called Hare system) is used in both the first and second calculation procedures.
In the first calculation procedure, each party initially receives as many seats in the regional constituency as the number of times the electoral quotient is contained in the vote number it has obtained.
A seat won in a regional constituency is also known as a basic seat. If a party wins such a seat, it can enter the National Council even if its strength nationwide remains below the required threshold of 4%. However, this has never been the case and is also extremely unlikely. Realistically, only larger parties have a chance of winning seats in regional constituencies.
2. Preliminary election (at the level of the provincial constituencies)
Only parties that have either obtained at least one seat in a regional constituency (basic seat) in the first preliminary election or have achieved at least 4% of the valid votes cast throughout the Federal territory may participate in the second preliminary election. All other parties are no longer allowed to participate in this preliminary election (or in the third) and have no chance of obtaining a seat.
Each party now receives as many seats as the number of votes in its total vote count in the provincial constituency. The seats already obtained in the first investigation procedure are deducted from this, and the remaining seats are allocated to candidates on the provincial party list.
3. Third calculation ("nationwide proportional adjustment")
Here, too, parties that have won at least one seat in a regional constituency or at least 4% of the valid votes nationwide take part. A further requirement is that the party has submitted a Federal election proposal (i.e. a list of candidates running at the Federal level) in good time.
In this procedure, all 183 seats are distributed using the electoral quotient, which is now calculated according to the D'Hondt method. To do this, the votes obtained by each party are written next to each other. These numbers are then divided by two and written below, then by three, four, five, etc. The numbers are then marked according to their size. The 183rd largest number is the electoral quotient for this calculation procedure. Each party then receives as many seats as the electoral quotient is contained in its party total. The seats allocated in the first and second calculation procedures must now be deducted again, and the remaining seats are allocated to candidates on the Federal election list.
Particularly small parties receive a large proportion of their seats in the third calculation procedure. (In the second calculation procedure, they usually receive seats only in large provinces).
In the 2017 National Council election, a total of 32 seats were allocated at the Federal level, 52 at the provincial level, and 99 in the regional constituencies.