المؤتمر السوري
He was elected to the central committee of al-Fatat in December 1918. In July 1919, following the Arab Revolt (1916–18) which succeeded in gaining Arab independence, al-Tamimi along with Izzat Darwaza, Sa'id Haydar and other members of al-Fatat's inner circle formed a group in the Syrian National Congress that rejected the establishment of any foreign mandate (British or French) in Greater Syria, claiming it would only be a "disguised form of imperialist penetration."