On January 22, 1967, Delaunay took part in a demonstration on Pushkin Square protesting the arrest Yuri Galanskov and others as well as articles 70 and 190 of the Soviet Penal Code—"Anti-Soviet agitation" and "Libel against the Soviet Government". He was arrested and given a one-year suspended sentence. His sentence was much lighter than that of another organizer of the same meeting, Vladimir Bukovsky, who got three years in a labor camp.
Dissidence
Delaunay's sentence required him to move away from Moscow, so he went to Novosibirsk State University to a friend and pupil of his grandfather, Aleksandr Aleksandrov. In Novosibirsk, he continued his philology studies and wrote poetry. At that time, his first official foreign publications appeared in the Paris magazine Grani N66. Delaunay was an organizer of a concert by the BardAlexander Galich, who was semi-legal at that time. At the beginning of 1968, after the court hearing for Galanskov and Ginzburg, Delaunay wrote an open letter to Literaturnaya Gazeta in which he praised their bravery. The letter was published in the New York City newspaper Novoe Russkoe Slovo.
In June 1968, Delaunay returned to Moscow. On August 25, 1968, he and seven other dissidents organized the now-famous demonstration in support of the Prague Spring in Red Square near the Moscow Kremlin. Delaunay and Pavel Litvinov held the famous banner with the words "ЗА ВАШУ И НАШУ СВОБОДУ". Seven people were arrested, and in court, Delaunay stated that the five minutes of freedom on the square were worth the awaiting years in prison. The sentence by the court was prepared in advance, just as for other defendants. Delaunay was sentenced to two years and 10 months in a labor camp that he served in Tyumen Oblast in western Siberia.
Emigration
In June 1971, Delaunay finished serving his sentence and returned to Moscow. In 1973, his wife Irina Belogorodskaya was arrested for her involvement with an underground journal, Chronicle of Current Events. In 1975, she was freed, and they both emigrated to France.
Death
On 13 June 1983, Delaunay died of a heart attack in Paris at the age of 35. In 1984, his book of poetry Verses: 1963-1983 was published. In that same year, he was posthumously awarded the Vladimir Dal prize. His poetry has been published in Russia since 1989.