In 1907, Bayar joined an unofficial branch of the Committee of Union and Progress (CUP) in Bursa. After the Second Constitutional Era was declared following the Young Turk Revolution, he served as the secretary-general of a newly founded local branch of the organization, with instructions to organize Unionist infrastructure in Anatolia. Bayar formed a Unionist militia in Bursa with the intention to join up with Mahmud Şevket Pasha's Action Army during the 31 March Incident. He got as far as Mudanya but by then the revolt was crushed. He then founded the İzmir branch of Union and Progress in 1911. Bayar established an organization and CUP mouthpiece known as "Halkın Doğru" (True to the People), where he wrote pro-CUP articles under the pseudonym Turgut Alp. He was a participant of the 1913 Ottoman coup d'état, and witnessed the murder of the Minister of War Nazım Pasha.