Former Senate President Ernesto Maceda graces the oath taking of the United Nationalist Alliance in Makati on July 1, 2015. Jonathan Cellona, ABS-CBN News

MANILA - Former Senate President Ernesto Maceda passed away Monday night following an operation over the weekend, his family announced.

He was 81.

Maceda's daughter-in-law Rica Vergara-Maceda said the veteran lawmaker had a gall bladder operation last Saturday.

Although he was fully conscious after surgery, Maceda slipped into a coma on Sunday. He was revived but died the next day.

The cause of death was multiple organ failure.

Maceda's son, Atty. Ernest Maceda, said his father was still on life support as of Monday noon. "Lumalaban pa," the younger Maceda had said.

Maceda served for 3 Senate terms - one during the pre-martial law Congress, two during the post-EDSA legislature.

He is best known for his privilege speeches exposing government anomalies and other controversial issues, earning him the moniker "Mr. Exposé."

Among his high-profile exposés was the PEA-Amari scam involving the overpriced purchase of reclaimed land in Manila bay, which he called "the grandmother of all scams."

Maceda also triggered a Senate probe on the so-called "Brunei Beauties" - female celebrities who were allegedly into high-class prostitution in the oil-rich state.

Before he ran for senator in the 1987 elections, Maceda was Cory Aquino's secretary of Environment and Natural Resources.

During his long and storied government career, Maceda also occupied five Cabinet positions.

MACEDA'S BEGINNINGS

Maceda started his illustrious 43-year political career in 1959 when he was elected as city councilor of Manila.

In 1966, he was appointed by then President Ferdinand Marcos as the Secretary of Community Development, becoming the youngest Cabinet member of the Marcos administration at 29.

Under the Marcos regime, he also served as Chairman of the Commission on Reorganization; Secretary of Commerce and Industry; and, Executive Secretary.

Maceda won his first Senate seat in 1971 and pushed for a bill granting protection to real estate buyers on installment basis.

He later broke from Marcos after the president declared Martial Law.

He then went on exile in the United States, where he became an aide and adviser of the late Senator Benigno Aquino.

Maceda returned to the Philippines when Aquino was assassinated in 1983, accompanying the senator's widow, Corazon Aquino, on the flight from Boston to Manila.

He became an opposition leader during the 1986 snap presidential election, which led to the EDSA People Power movement and the overthrow of the Marcos regime.

POST-EDSA YEARS

After the peaceful revolution that installed President Corazon Aquino into power, Maceda headed the Ministry of Natural Resources.

In 1987, he won a senatorial seat under the Aquino administration's ticket. He later served as Senate President from 1996 to 1998.

The politician who hailed from Pagsanjan, Laguna was also the recipient of more than 40 national and international honors and awards.

He also served as ambassador to the United States from 1999 to 2001 during the Estrada administration.

Maceda earned his bachelor of Laws degree, cum laude, from the Ateneo de Manila University. He also held a Doctorate in Public Administration from the Polytechnic University of the Philippines and a Doctorate in Education from the Philippine Normal University.

He had five children with his wife, Marichu Vera Perez.