the Soviet Union, the PZPR leadership split into two factions, dubbed Natolinians and Puławians. The Natolin faction – named after the place where its meetings took place, in a government villa in Natolin – were against the post-Stalinist liberalization programs (Gomułka thaw). The most well known members included Franciszek Jóźwiak, Wiktor Kłosiewicz, Zenon Nowak, Aleksander Zawadzki, Władysław Dworakowski, Hilary Chełchowski. The Puławian faction – the name comes from the Puławska Street in Warsaw, on which many of the members lived – sought great liberalization of socialism in Poland. After the events of Poznań June, they successfully backed the candidature of Władysław Gomułka for First Secretary of party, thus imposing a major setback upon Natolinians. Among the most prominent members were Roman Zambrowski and Leon Kasman. Both factions disappeared towards the end of the 1950s. Initially very popular for his reforms and seeking a "Polish way to socialism", and beginning an era known as Gomułka's thaw, he came under Soviet pressure. In the 1960s he supported persecution of the Roman Catholic Church and intellectuals (notably Leszek Kołakowski who was forced into exile). He participated in the Warsaw Pact intervention in Czechoslovakia in 1968. At that time he was also responsible for persecuting students as well as toughening censorship of the media. In 1968, he incited an anti-Zionist propaganda campaign, as a result of Soviet bloc opposition to the Six-Day War. In December 1970, a bloody clash with shipyard workers in which several dozen workers were fatally shot forced his resignation (officially for health reasons; he had in fact suffered a stroke). A dynamic younger man, Edward Gierek, took over the Party leadership and tensions eased. Gierek's economic opening In the late 1960s, Edward Gierek had created a personal power base and become the recognized leader of the young technocrat faction of the party. When rioting over economic conditions broke out in late 1970, Gierek replaced Gomułka as party first secretary. Gierek promised economic reform and instituted a program to modernize industry and increase the availability of consumer goods, doing so mostly through foreign loans. His good relations with Western politicians, especially France's Valéry Giscard d'Estaing and West Germany's Helmut Schmidt, were a catalyst for his receiving western aid and loans. The standard of living improved in Poland in the 1970s, the economy, however, began to falter during the 1973 oil crisis, and by 1976 price hikes became necessary. New riots broke