Lipiński became one of the prominent critics of the government. His position as a known Marxist economist shielded him to certain extent from government persecution and allowed him to say things many others were unable to. Till the very end he remained convinced that some form of socialism is preferable to capitalism. He signed three public letters criticizing the communist government: the Letter of 34 in 1964, the Letter of 59 in 1975 and the Letter of 14 in 1976. In 1977 he was expelled from the PZPR.