In addition to his work as a journalist, Sidik was involved in several pro-independence organizations, becoming a member of the Partindo and Gerindo political parties during the 1930s.

During the Japanese occupation of the Dutch East Indies, Sidik became the local head of the Putera and Jawa Hokokai organizations in Kediri.

[1] During the Japanese occupation of the Dutch East Indies, Sidik became the local head of the Putera and later the Jawa Hokokai organizations in Kediri.

[3] On the same day that Sartono withdrew, Sukarno appointed Sidik and Soekiman Wirjosandjojo of the Masyumi Party as formateurs.

[5] After several weeks of negotiations, both parties agreed to an equal share of posts in the cabinet, with the Masyumi returning to the office of prime minister.

When Prawoto and Sidik failed to reach an agreement, Sukarno appointed former Labor Minister Wilopo as formateur.

[6] While visiting the Indonesian National Party branch in East Java, Sidik grew fatigued and was brought to the Surabaya General Hospital on 6 September 1955, accompanied by future PNI chairman Ali Sastroamidjojo.

[10] His death became headline news in several PNI-affiliated newspapers, including the left-wing nationalist Berita Indonesia paper.