membership). The reform-promising Gomułka of 1956 turned into the authoritarian Gomułka of the 1960s. Although Poland enjoyed a period of relative stability in that decade, the idealism of the "Polish October" faded away. The decisions made at the XIII Plenum of the Central Committee, held in 1963, meant a definite end of the post-October liberalization period. The demise of Gomułka's tactical allies, the Puławy faction, gradually replaced by Gomułka's own people, was apparent when Roman Zambrowski, the leading Jewish politician, was removed from the Politburo. Poland under Gomułka's rule was generally considered one of the more liberal communist states. However, Poles could still go to prison for writing political satire about the party leader, as Janusz Szpotański did, or for publishing a book abroad. A March 1964 "Letter of the 34", signed by leading intellectuals and delivered to the office of Prime Minister Cyrankiewicz, criticized the worsening censorship and demanded a more open cultural policy, as guaranteed by the constitution. Jacek Kuroń and Karol Modzelewski were expelled from the party and from 1965 imprisoned for written criticism (an "Open Letter to the Party") of the party rule and pointing out the contradictory nature of the supposedly workers' state. Kuroń and Modzelewski accused the regime of betraying the revolutionary cause; like many younger Polish reformers, they spoke from leftist positions and were ideologically closely aligned with Western radicals of the 1960s. As the regime was getting less liberal and more repressive, Gomułka's popularity declined as his initial vision lost its impetus. Many Poles found Gomułka's self-righteous attitude irritating and his demeanor provincial. He reacted to increasing criticism by refusing to budge and insulating himself with the help of cronies, of whom Zenon Kliszko was the most influential. Within the party, Minister of the Interior Mieczysław Moczar and his nationalist-communist faction known as "the Partisans" (together with Moczarowcy, the much broader system of Moczar's political clientele) were looking for an opportunity to assert their dominance. By the mid-1960s, Poland was starting to experience economic difficulties and the appreciable thus far standard of living improvements were showing signs of stagnation (during 1960–70 real wages for workers grew only by an average of 1.8% per year). The postwar economic boom was ending and the increasingly globalized and integrated world economy was becoming inhospitable to national developments operating behind trade barriers. Like the other communist states, Poland was spending too much on heavy industry, armaments