 Landau was among the founders of the Herut, and was a member of the first to eighth Knessets.He was a member of the Begin cabinet, serving as Minister of Development in 1967–1970 and despite not retaining his seat in the 1977 elections, was made Minister of Transport by Menachem Begin, a role he retained until the 1981 elections.After his death, the Ministry of Transportation renamed Highway 5 after him.