After the war Hoste took over the management of the publishing company, and Het Laatste Nieuws became the most popular newspaper in Flanders.

Julius Hoste would become president of the Algemene Belgische persbond (1935–1936), and secretary of the Verbond der Brusselse dagbladbestuurders (1939).

In 1935 he entered the political scene, and campaigned against the fascist parties Rex and VNV, and in 1936 became Minister of Education in the second government of Paul Van Zeeland.

While he was in office, he founded the Koninklijke Vlaamse Academie voor Wetenschappen, Letteren en Schone Kunsten and a Dutch and French cultural council (1938).

As a politician he paid attention to the problems of the Belgian communities (Flanders and Wallonia) and world peace during the Cold War.