Career
Born in Volodymyrets in the Russian Empire (today in Ukraine), Shostak joined the Betar movement in 1930 and made aliyah to Mandatory Palestine in 1935. He joined the Betar work battalion in Herzliya, and in 1936 was elected secretary of the National Workers Labour Federation. However, he entered the Knesset as a replacement for Ya"akov Meridor in November 1951.
He was re-elected in 1955, 1959, 1961 and 1965.
During the Herut convention in 1966 he and Shmuel Tamir constituted the major opposition to Begin"s leadership of the party, and the following year he and three other Herut MKs left the party to form the Free Centre. He was re-elected again in 1969, and in 1973 the Free Centre allied with Herut and the Liberal Party to form Likud, for whom he was elected to the Knesset in the elections that year.
In 1975 the Free Centre split and Shostak became chairman of the Independent Centre faction. He was re-elected again in 1977, and was appointed Minister of Health in Begin"s government.
He retained the role following the 1981 elections, but was left out of the cabinet after the 1984 elections, but was appointed Deputy Speaker of the Knesset.
He finally lost his seat in 1988, having served in the Knesset for just over 37 years.