"In the secrecy of the polling booth, God sees you - Stalin doesn't," read Catholic election posters on the eve of the first parliamentary elections in post-war Italy.
Pope Benedict XVI wants Italians to back the boycott
It was 1948, and the Vatican knew all too well that a high turnout was crucial, especially in rural areas where people's religious values were stronger.
Marxism was openly anti-clerical, and a no-holds-barred election campaign by Catholic forces depicted a future of war and misery for the country if the Communists won.
Cardinals and parish priests held sermons in which they threatened supporters of Marxism with excommunication, while thousands of Catholic volunteers across the country urged people to go to the polls to save themselves and their children from the "evil of Bolshevism".
It was a huge success for Catholics: almost 90% of those entitled to vote cast their ballot, and the Christian Democrats won more than 50% of the seats in parliament.
Almost 60 years have passed. Italy is holding a referendum on the contentious issue of fertility treatment and embryo research, and this time the Holy See knows a turnout of less than 50% would make the vote null and void.
Pope Benedict XVI has sent a clear message to Italians: he has urged them to follow the cardinals' advice to boycott the vote.
"Life cannot be put to a vote: don't vote," read giant billboards by advocates of the boycott, bearing a picture of a mother with her child.
But will the Vatican's message really deter Italians from speaking their minds?
Many people have been asking themselves whether they would run the risk of being expelled by the Church by casting their ballot.
Cardinal Francesco Pompedda, a top authority in Catholic ecclesiastical law, has the answer.
"There will be no excommunication, but [going to the polls] is a serious and impudent act of disobedience," he said.
Indeed, some of the most prominent and outspoken politicians have been exceptionally reserved in the run-up to the referendum - be it to avoid alienating part of the electorate or displeasing the Vatican.
'Matter of conscience'
Even the usually vociferous Prime Minister Silvio Berlusconi did not indicate if and how he would vote.
And Romano Prodi - who, despite leading the centre-left opposition, is a former Christian Democrat - gave a rather cryptic reply to journalists who were trying to get him to speak out on the issue.
"I am going to vote because by doing so I can express my will. It might be a "No", a "Yes" or an abstention, and that will be evaluated in the depths of my conscience," he told reporters.
Campaign posters in Italy say that abstaining is "a natural act"
He later said his silence on the issue had been exploited and he would vote according to his "ethical and religious views".
The Vatican could not prevent Italians from legalising divorce and abortion in two landmark referendums held in 1974 and 1981 that marked some of Italy's more radical social changes.
But this time, a defeat is looming for those who want to soften the current restrictions on assisted fertility.
And the new Pope, Benedict XVI, whose next move is widely expected to be a campaign to repeal Italy's abortion law, seems set to seize his first political victory.