Lucman was serving in congress on 18 March 1968, when the
Jabidah massacre took place. The Marcos administration had gathered a group of
Tausug recruits for an operation called "Project Merdeka" (
merdeka being the Malay "freedom"). The military began training them on the island of
Corregidor to form a secret commando unit called "Jabidah," which would destabilize and take over Sabah. The trainees eventually rejected their mission, for reasons that are still debated by historians today. Whatever the reasons behind their objections, all but one of the recruits were killed. The survivor, Jibin Arula, escaped with a gunshot to his leg and was able to tell his story to the press. In Lanao del Sur, Domocao Alonto established the Ansar El Islam (Helpers of Islam) along with Sayyid Sharif Capt. Kalingalan Caluang,
Salipada Pendatun, Hamid Kamlian, Udtog Matalam, and Atty. Macapantun Abbas Jr. Accordingly, "it is a mass movement for the preservation and development of Islam in the Philippines". When opposition senator
Benigno Aquino Jr. came out with an exposé alleging that Marcos was ultimately culpable for Jabidah, Lucman called for Congress to begin proceedings to impeach President Marcos. When his proposal didn't get enough congressional support, he became convinced that Muslims should rule themselves in Muslim Mindanao – a conviction he continued to hold after the end of his term as congressman in 1969. == After Congress ==