A lawyer by profession, Harb first held political office when elected in 1972 as the Maronite deputy for Batroun, in the North Governorate of Lebanon, being appointed public transport minister for labour and minister of the national education and art schools in 1979 in Salim Hoss's government, and remaining minister until 1980. From 1990 to 1992 Harb returned to the education ministry in the cabinet of then Prime MinisterOmar Karame. Harb was credited with helping negotiate the Taef Agreement, which brought the Lebanese civil war to an end by electing a power sharing agreement within the Lebanese Parliament, giving Christians and Muslims equal representation in Parliament by assigning seats to sects. He was a member of the opposition during the governments of Rafik Hariri; in particular to Nassib Lahoud, Salim Hoss, Omar Karami, Mohammad Youssef Baydoun and Hussein Husseini. He announced his candidacy for the Lebanese Presidency during the 1998 elections but withdrew his nomination the day the polls began. Émile Lahoud was unanimously elected. After a short period of support for the government of Salim Hoss in 1998, he rejoined the opposition. In 2000, he broke his alliance with Nayla Moawad and Omar Karami, and allied himself at the election booth with Soleiman Franjieh Jr, and the Tripoli Bloc of Mohammad Safadi and Najib Mikati. In the general elections held in 2000, Harb won the seat of Batroun, the second district of north Lebanon. In 2001, as one of the founding members of the Qornet Shehwan Gathering, he strongly expressed his opposition to the policies of the Hariri government and to Syrian hegemony. In 2004, Harb participated, with Nayla Moawad, Omar Karami, Salim Hoss, Hussein Husseini and Albert Mansour, in the creation of a National Face for Reform. In 2004, he declared himself a nominee for the Presidency of Lebanon, however due to a Syrian-engineered constitutional amendment extending the term of President Émile Lahoud, he was unable to run. He then broke his alliance with Omar Karami who he considered to be too pro-Syrian. In 2005, after the assassination of former Prime Minister Rafik Hariri, Harb joined the massive protests and demonstrations against the Syrian occupation of Lebanon and demanded that Syrian troops withdraw immediately. Like many other, he accused the Syrian government of ordering the death of Rafiq Hariri. As a member of the 14 March Alliance, he was one of the several candidates to run for the Lebanese Presidency in 2008, but all major parties decided to elect a compromise candidate, Michel Sleiman. Harb is the lawyer of the Tueni family, and filed a lawsuit against two Syrian officers due to their alleged roles in Gebran Tueni's assassination in December 2005. Boutrs Harb is the elected head of the Board Of Directors of the American University of Science and Technology.
In 2007, Harb called for the integration of Hezbollah's military arm into the Lebanese Army. Wikileaks cables indicated that he had told the U.S.' diplomats in Lebanon during the 2006 Lebanon War that an Israeli operation to control Hezbollah's strongholds of Maroun al-Ras and Bint Jbeil could enable a U.S.-brokered ceasefire and that Syria will not be a part of the solution to the crisis. He also said that Hassan Nasrallah cannot be allowed to appear as a hero to the region, despite his rising popularity as a result of a wave of sympathy.
Assassination attempt
Following an attempt to assassinate fellow March 14 movement member and head of Lebanese ForcesSamir Geagea, in early July 2012 Harb escaped an assassinate attempt, which a government official said was "part of a series of assassination attempts" against Lebanese politicians. Harb commented that he had been warned by Lebanese security forces that they had found "bomb detonators in a lift" at his Beirut office.
