laurent fabius (; born 20 august 1946) is a french politician of jewish descent. he was president of the constitutional council since 8 march 2016. he has been a member of the socialist party. he was the prime minister of france from 17 july 1984 to 20 march 1986. fabius was 37 years old when he was appointed and is, so far, the youngest prime minister of the fifth republic.