Philippine lawmakers failed Wednesday to pass a crucial bill aimed at ending a decades-long Muslim insurgency that has claimed tens of thousands of lives, igniting fears of fresh violence. President Benigno Aquino, whose six-year term ends in June, had lobbied hard for the passage of the bill, which would have granted the nation's Muslim minority an autonomous southern homeland. However he was unable to muster enough support in the lower house of Congress to even secure a vote by Wednesday, the final day of parliament before it adjourns ahead of national elections in May. Failure to pass the bill means it can not be passed under Aquino, who is limited by the constitution to a single term, with no certainty over whether his successor will even pursue a peace deal. Asked if the failure to pass the bill could spark violence, chief government peace negotiator Miriam Coronel-Ferrer told AFP: "That's the danger, that's why we are taking steps, calling for sobriety." The nation's largest Muslim rebel group, the 10,000-strong Moro Islamic Liberation Front (MILF), signed a peace accord with Aquino's government in 2014 to end its struggle for independence, which began in the 1970s. Under the accord, the rebels would have only given up their arms after the law was passed creating the autonomous homeland and a regional government was elected. The vote was meant to take place alongside the May general election. After the collapse in 2008 of the last attempt to seal a peace deal with the MILF, hardline rebels raided Christian farming villages, triggering fighting that left more than 400 people dead and 600,000 displaced. Chief MILF negotiator Mohagher Iqbal said Wednesday the rebel leadership was working hard to avoid a repeat, and vowed to continue working for peace with Aquino's successor. He told ABS-CBN television there could be a feeling of "repression" within the MILF ranks, but the leadership was countering with "massive engagement". "We just explain to them that here lies the problem in the peace process. We will never cease engaging in the peace process," he told ABS-CBN television. Most political analysts say Aquino lost lawmakers' support for the autonomy bill after a police raid in MILF territory last year killed a Malaysian bomb maker on the United States' list of most-wanted "terrorists". However the raid led to a day of intense fighting with the MILF and other rebels that left 44 police commandos dead.