During the First Quarter Storm, he was a member of "Samahang Demokratiko ng Kabataan" (Democratic Association of the Youth) in the 1970s. After only a year in college at the University of the Philippines, he decided to go underground and do full-time organizing work in the factories and urban poor communities in the northern sector of Metro Manila. Ka Popoy was elected Secretary of the Manila-Rizal Regional Party Committee of the CPP in the mid-70's and spearheaded the broad formation which challenged the Marcos dictatorship in 1978 Batasan Pambansa elections. The Central Committee of the CPP admonished Ka Popoy and the whole regional committee for advocating participation in 1978 Batasan Pambansa elections because it ran counter to the CC call to head to the counryside to wage armed struggle against the dictatorship. Ka Popoy was only to return at the helm of the Manila-Rizal Regional Party Committee after the EDSA uprising of 1986. In spite of the differences with the central leadership, Ka Popoy strived harder to strengthen revolutionary work in the capital city.