In 1960 he began to work secretly in the student movement against the U.S.-backed South Vietnam regime during the Vietnam War.

Two years later he joined the National Front for the Liberation of South Vietnam and worked in the education subcommittee in Ben Tre Province. In 1975 he was sent to the north to attend the Central Propaganda School in Hanoi.

In 1978 he became deputy head of the propaganda committee of the Ben Tre Province Party Committee, and in 1982 took over as Party chief of Giong Trom District.

At the 1986 National Party Congress he was elected an alternate member of Central Committee of the Communist Party of Vietnam.

At the next congress five years later he was elected an official member and also a member of the Central Inspection Committee, the Party organ that is responsible for combating corruption, disciplining Party members.

In 1998 the Politburo, the main decision-making body of the Party, named him head of the Central Internal Political Protection Committee, an advisory body to the Party Central Committee.

Two years later he became Party Committee chief of Dong Thap Province.

In 2001 he became head of the Central Committee for Internal Affairs, where he issued and advised decisions that led to important reformation in Vietnam's justice system.

At the 2006 congress, he was reelected to the Party Central Committee and made a member of the Politburo.

In June that year he became deputy PM, a position he held until he retired in 2011.