Appalled at the prospect of an anti-communist Pole leading the Roman Catholic church, KGB bosses allegedly gave orders to destroy John Paul II hours after his election in 1979.
Operations - codenamed Pagoda and Infection - allegedly instructed intelligence agencies in the Warsaw pact countries to "discredit the church and the Pope with disinformation and provocations that do not exclude his physical elimination".
The claims were contained in 47 pages of documents released to the Italian parliament's terrorism commission.
Italy's domestic secret service, Sisde, is believed to have obtained the papers from the then Czechoslovakia in 1990.
The archive vindicated claims that the Soviet Union was behind the March 1981 assassination attempt on the Pope in St Peter's Square, Rome, according to excerpts published in yesterday's Il Giorno newspaper.
It has never been proved that the gunman, Mehmet Ali Agca, a Turkish member of the Grey Wolves terrorist group, was working for Moscow.
KGB agents plotted to plant a bug in a statue of the Madonna kept on a table in the private study of the late Vatican secretary of state, Cardinal Agostino Casaroli, according to the files. A plan to put another bug in a picture frame was also alleged.
The KGB wanted to be able to anticipate and combat the Vatican's stoking of anti-communist sentiment in eastern Europe.
Markus Wolf, who headed East Germany's Stasi secret service, has claimed that a Benedectine monk who worked inside the Vatican was a mole.
The terrorism commission promised to investigate all the allegations. The Italian secret service is believed to possess another 600 pages of Czechoslovak documents. They were handed over after Vaclav Havel became president.
Enzo Fragala, a member of the rightwing Alleanza Nazionale, said it was clear that the Soviet Union wanted to destroy one of the gravest threats to its empire. "The Soviets succeeded in organising a frontal attack on the Vatican and the Pope," he said.
The Vatican declined to comment on the allegations.