Pope Benedict XVI was set to commemorate the 50th anniversary of the death of pope Pius XII on Thursday as the Vatican vowed that history would exonerate the controversial Nazi-era pontiff.
The Vatican newspaper Osservatore Romano devoted an editorial and two articles to the event in its Wednesday edition, vowing to combat what it called a "black legend" painting Pius XII as indifferent to the Holocaust or even "pro-Nazi".
"History will exonerate Pius XII," wrote Italian historian Paolo Mieli, adding: "The Jewish community was grateful to him" after World War II.
Pius XII, who died in 1958, is a candidate for beatification.
The commemorative mass will come just three days after the Grand Rabbi of Haifa, Israel, spoke out against such an honour for the late pope.
Shear-Yushuv Cohen, who on Monday became the first Jew to address a synod of bishops at the Vatican, said Pius XII "should not be seen as a model and he should not be beatified because he did not raise his voice against the Holocaust."
Benedict XVI will celebrate the commemorative mass at St Peter's Basilica on Thursday morning.
On Tuesday one of the Vatican's most senior cardinals defended Pius XII's wartime record.
Secretary of State Tarcisio Bertone wrote in the Osservatore Romano that Pius XII had been "neither silent nor anti-Semitic, but he had been prudent."
If the then pope "had intervened publicly, he would have endangered the lives of thousands of Jews who, at his request, were hidden in the 155 convents and monasteries in the city of Rome alone," he added.
Cardinal Bertone's remarks come from the preface to a forthcoming book on Pius XII which the Osservatore Romano chose to publish Tuesday.
The cardinal argued that it was "profoundly unjust" to attack Pius XII over his wartime position, "forgetting not only the historical context but also his immense charity work" for Jews.
The process of beatifying Pius XII, which was launched in 1967 and is approaching completion, would place him one step away from sainthood. It has sparked bitter debate and tension between Catholics and Jews.
Opponents, including the Simon Wiesenthal Centre, accuse Pius, who headed the Roman Catholic Church from 1939 to 1958, of having remained silent during the Holocaust that killed an estimated six million Jews.
Supporters, including the US-based Pave the Way foundation that organised a symposium on the issue last month, claim the pope worked intensively to save Jews and has been the victim of a slander campaign.
Last year, Benedict created a special commission to study the question of his beatification.
The pontiff praised Pius in September for "not sparing his efforts" to save Jews from extermination.