In 1956, along with György Lukács and Gyula Háy, he was expelled from the Party for criticizing its leadership. In the same year, he wrote "Niki: The Story of a Dog", a fable about the arbitrary restrictions on human life in Stalinist Hungary. Later that year, he became a spokesman for the Revolutionary government. When the revolution was quashed, in 1957, he was sentenced to nine years in prison. That sentence was suspended in 1961 and he received a full amnesty in 1963.