Codenamed Operation Bloc (Russian: Операция «Блок», romanized: Operatsiya «Blok»; Ukrainian: Операція «Блок», romanized: Operatsiia «Blok»), the purge resulted in the arrest of 193 people, including most of the leaders of the Ukrainian dissident movement, as well as the removal of Petro Shelest and the installation of Volodymyr Shcherbytsky as First Secretary of the Communist Party of Ukraine.

[3] Shelest's greater tolerance for Ukrainian national expression proved intolerable to Brezhnev,[4] and moves began being made to dampen his authority.

[3] Prior to the execution of Operation Bloc, Belgian foreign student Yaroslav Dobosh, a member of the Organisation of Ukrainian Nationalists in exile, was dispatched at the recommendation of Omelian Koval [uk] and the blessing of cardinal Josyf Slipyj to the Soviet Union on a mission to acquire samvydav.

During his detention, eight rolls of film including Karavanskyi's Dictionary of Rhymes in the Ukrainian Language and photos of dissidents Vasyl Stus and Valentyn Moroz were found, in addition to books that KGB officers incorrectly believed to be samvydav (including a tourist brochure of Saint Andrew's Church in Kyiv).

Under interrogation, Dobosh admitted his membership in the OUN and the Ukrainian Youth Association, as well as the fact that Koval had sent him to the Soviet Union.

[6] On the eve of the purge, leading Ukrainian dissidents gathered in the Lviv flat of Olena Antoniv[7] to hold a Vertep (nativity play) ceremony for the holiday of Koliada.

Further complicating matters, Shelest had the support of the leaders of other union republics, such as Ivan Bodiul of Moldavia or Vasil Mzhavanadze of Georgia.

At the same meeting, Brezhnev told Chairman of the Council of Ministers of Ukraine Volodymyr Shcherbytsky, leader of the party opposition to Shelest, "get ready to be First Secretary."

[13] Kremlinologists in the West initially believed that Shelest's hardline foreign policy positions, such as his opposition to a planned visit by U.S. President Richard Nixon, had caused his removal.

Shelest's rule had led to a significant increase in party membership, particularly in traditionally nationally conscious western Ukraine.

Even among those who were not arrested, an oppressive attitude and constant surveillance remained over them, and many were forced to either live in exile (such as Lina Kostenko, Mykhailyna Kotsiubynska, Valeriy Shevchuk, Les Tanyuk, and Pavlo Movchan) or publicly express support for the Soviet government (as was the case with Ivan Drach and Dmytro Pavlychko).