 But on June 12, 1978, when the Interim Batasang Pambansa was inaugurated as mandated by the 1973 Constitution as the country shifted from a presidential to a parliamentary form of government, it automatically abolished the two houses of Congress.The offices of the Senate majority and minority leaders were also automatically abolished.On July 27, 1987, 5 months after the EDSA Revolution that toppled the Marcos administration, the bicameral Congress resumed its session after 15 years of its abolition.