Lobregat was present in Malacañang Palace on October 12, 1936, when President Manuel L. Quezon created and established the chartered city of Zamboanga during the Philippine Commonwealth.

Before 1971, Lobregat, was president of the Philippine Coconut Producers Federation (COCOFED), and was subsequently elected to the 1971 Constitutional Convention representing Zamboanga City.

With Marcos gone and the then opposition-turned-administration splitting into factions, Lobregat easily won as representative of the Lone District of Zamboanga City in the 1987 legislative elections and was reelected in 1992 and 1995.

Lobregat, always seen in public wearing kimona and patadyong, was among three female representatives who figured prominently in the protest actions against the creation of the Southern Philippines Council for Peace and Development (SPCPD) in 1996.

She, along with then South Cotabato representatives Luwalhati Antonino and Daisy Fuentes, were referred to by the media as “Tres Marias.” Lobregat was a harsh critic of Moro National Liberation Front chair Nur Misuari, insisted that the controversial coconut levy funds were private funds; campaigned against the inclusion of her city in the Autonomous Region in Muslim Mindanao in the 1989 and 2001 plebiscite; ordered Filipino deportees from Sabah, Malaysia in 2002 to be “screened” before entering the city, opposed the transfer of the seat of the Zamboanga Peninsula Region from Zamboanga City to Pagadian and was an avid supporter of the Balikatan joint military exercises between the Philippines and the United States.