After the 1968 election, Pintor is elected to the Chamber of Deputies with the Italian Communist Party, which he left after the 1968 invasion of Czechoslovakia by the Soviet Union. In 1969, Pintor is one of the founders, together with Lucio Magri, Rossana Rossanda and Luciana Castellina, of the left-wing newspaper Il manifesto: Pintor is later appointed editor-in-chief from 1971 to 1975, from 1976 to 1978 and from 1991 to 1995.