removed from the leadership at the 1984 party congress. A powerful faction in the party, led by François-Xavier Katali, favored a hard-line pro-Soviet position; Sassou Nguesso was able to marginalize the Katali faction at the 1984 congress. Katali was demoted to a minor government ministry, but suffered no further punishment; when he died of a heart attack in 1986, he was considered a national hero. Serious unrest in 1990 resulted in the collapse of the PCT regime. Sassou Nguesso was forced to introduce multi-party politics in 1990 and then call a National Conference in 1991. The National Conference saw severe criticism of Sassou Nguesso and repudiated PCT rule; it set up a non-PCT transitional government and reduced Sassou Nguesso to figurehead status. Multi-party era The PCT was in opposition from 1992 to 1997, during the presidency of Pascal Lissouba. Although Marxist–Leninist ideology was abandoned, the party remained loyal to Sassou Nguesso and it continued to be dominated by key figures from the one-party era. Sassou Nguesso ultimately returned to power in the June–October 1997 civil war. Denis Sassou Nguesso, presidential candidate of both the PCT and the United Democratic Forces coalition, won the March 2002 presidential election with 89.4% of the vote; there were no serious opposition candidates. The PCT won 53 out of 137 seats in the National Assembly in the May–June 2002 parliamentary election; together with smaller, allied parties, it held a parliamentary majority. At the party's Fifth Extraordinary Congress in December 2006, Sassou-Nguesso was re-elected as President of the Central Committee of the PCT and Ambroise Noumazalaye was re-elected as Secretary-General of the PCT; the Central Committee elected at the 2006 congress included more than 500 members (there were previously less than 150 members), while the Political Bureau elected on the same occasion included more than 60 members and the Permanent Secretariat included 15 members. Social democracy was also adopted as the party's new principal ideology. The political landscape in Congo-Brazzaville has been highly fractured since the early 1990s. In an effort to consolidate support for Sassou Nguesso, an initiative to "refound" the PCT as a broader party was attempted in 2006. Although backed by Secretary-General Noumazalaye, the effort encountered firm opposition from PCT "conservatives", led by Justin Lekoundzou, who wanted to preserve the PCT as a distinct party. Noumazalaye died in November 2007, and Prime Minister Isidore Mvouba became Interim Secretary-General of the PCT. In the