Additionally, an election is held to replace Federal Councillors who have announced their retirement or who have died in office.
Non-reelection of a candidate has occurred only four times in the history of the Swiss federal state, twice in the 19th century (Ulrich Ochsenbein 1854), Jean-Jacques Challet-Venel 1872) and twice in the 21st (Ruth Metzler-Arnold 2003, Christoph Blocher 2007).
Since 1999, the constitution requires that the Federal Council duly represents all regions and linguistic groups.
The "Stammlande" principle traditionally elected only Councillors whose party held a majority in their own canton of origin.
A pure plurality voting system would likely result in a Federal Council composed exclusively of representatives of the urban, German-speaking cantons, which account for a majority of the Swiss population.