Since earlier periods of the CCP, Mao Zedong's emphasis on collective farms as the correct form of rural socialism differed from Liu Shaoqi and Zhang Wentian's line of supporting the supply and marketing cooperative(SMCs). Gao Gang was a prominent leftist and a staunch supporter of Stalin's and Mao's model of bolstering collectivization. Zhang Wentian clashed with Gao Gang when Zhang strongly criticized the idea of organizing all peasants into mutual aid teams. Soon afterwards, the CCP suddenly appointed Zhang as a Chinese delegate to the United Nations without consulting him. Zhang reluctantly accepted the post and repeatedly made pleas to return to his job in the economic sector, but they were ignored. In April 1951, Zhang Wentian was appointed as Ambassador of China to the Soviet Union. Zhang Wentian paid attention to studying international issues and actively submitted the analysis and policy proposals to the Central Government. For instance, the report on the first armistice negotiations in the Korean War was put forward in 1951, and was valued by the Central Government. In 1953, during his conversation with Wu Lengxi of Xinhua news agency, Zhang talked about the weakness and failures of the Soviet collectivization system and warned that China should not blindly copy the Soviet model. In January 1955, Zhang Wentian returned to China and was appointed the first deputy minister of foreign affairs of the People's Republic of China to assist Zhou Enlai in diplomatic affairs. In September 1956, the 8th National Congress of the Communist Party of China elected Zhang Wentian as alternate member of the Political Bureau of the CPC Central Committee.