Good question. I'm not sure exactly how the successor is chosen, but this section from Wikipedia indicates just the one member is replaced: > Until 1999, the

Good question. I'm not sure exactly how the successor is chosen, but this section from Wikipedia indicates just the one member is replaced: > Until 1999, the Constitution mandated that no canton could have more than one representative on the Federal Council. Until 1987, the place of origin was used to determine which canton a Federal Councilor was from. After 1987, the place of residence (or, for councilors who were previously members of the Federal Assembly or of a Canton's legislative or executive body, the canton from which they were elected) became the determinant factor. Nothing prevented candidates from moving to politically expedient cantons, though, and the rule was abandoned in 1999. Since then, the Constitution has mandated an equitable distribution of seats among the cantons and language regions of the country, without setting concrete quotas. Whenever a member resigns, he/she is generally replaced by someone who is not only from the same party, but also the same language region. In 2006, however, Joseph Deiss, a French Swiss, resigned and was succeeded by Doris Leuthard, a German-speaking Swiss, and in 2016, Eveline Widmer-Schlumpf, German-speaking, was succeeded by Guy Parmelin, a French Swiss.