The Congolese Party of Labour (, PCT) is the ruling party of the Republic of the Congo. Founded in 1969 by Marien Ngouabi, it was originally a pro-Soviet, Marxist–Leninist vanguard party which founded the People's Republic of the Congo. It took a more moderate left-wing stance following the dissolution of the Soviet Union in 1991 and adopted social democracy as its principal ideology in 2006. Denis Sassou Nguesso is the President of the PCT Central Committee, and Pierre Moussa is the Secretary-General of the PCT. One-party rule The PCT was founded by President Marien Ngouabi on 29 December 1969, and was Congo-Brazzaville's sole ruling party from its inception. From the outset, it was heavily dominated by military officers from the sparsely populated north of Congo-Brazzaville. Although the PCT regime was designed as a Soviet-style socialist one-party state, it was essentially a military regime with a strongly ethno-regional character. Members of the southern ethnic groups, who were far more numerous than northerners, were included in the power structure, but the top leaders were consistently northerners. Ideologically, the party represented a spectrum of Marxist–Leninist views and suffered from internecine struggles in the 1970s, which sometimes turned violent. Some leaders on the left-wing of the party, such as Ange Diawara and Claude-Ernest Ndalla, favored a radical pro-Chinese position; they unsuccessfully attempted a coup d'etat against Ngouabi in February 1972. The right wing of the party, which was derided as having only a superficial commitment to Marxism–Leninism, was represented by Joachim Yhombi Opango; the 1972 plot was inspired by the left wing's loathing for Yhombi Opango. Ngouabi was assassinated under unclear circumstances in March 1977 and succeeded by Yhombi Opango, whose opponents in the PCT were angered by his rightist deviationism and perceived marginalization of the party, and they ousted him in a February 1979 technical coup, installing Denis Sassou Nguesso—another career officer from the north—in power. The elevation of Sassou Nguesso, who represented the PCT's left-wing, marked a return to party orthodoxy. Sassou Nguesso was neither a radical leftist nor an ideologue; his policies were generally marked by pragmatism, and he sought warm relations with the West as well as the Eastern Bloc. As Sassou Nguesso consolidated power, PCT factionalism was less pronounced during the 1980s, although internal power struggles continued. Jean-Pierre Thystère Tchicaya, a leftist ideologue who was one of the PCT's top-ranking leaders, was accused of organizing a bomb plot and