Mr Fini dropped neo-fascism to enter mainstream politics
Italy's parliament speaker has criticised the Roman Catholic Church for failing to do enough to oppose anti-Semitic race laws in 1938.
Gianfranco Fini, who began his career in a neo-fascist party, was speaking at a ceremony marking the 70th anniversary of the adoption of the laws.
Vatican Radio quickly reacted by denying his accusations.
The 1938 laws led to the deportation of thousands of Jews to Nazi concentration camps where many of them died.
The laws - adopted by Italy's fascist leader Benito Mussolini - also prevented Jewish people from holding posts as civil servants or teachers.
"We must ask ourselves why Italian society embraced the anti-Jewish legislation and why, beyond certain laudable exceptions, there were not demonstrations of real resistance," Mr Fini, the speaker of the chamber of deputies, said on Tuesday.
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''Not even, it hurts me to say, by the Catholic Church," he added.
It was surprising to many Italians that Mr Fini - who once described himself as a fascist but later entered mainstream Italian politics - chose the commemoration ceremony to openly criticise the Vatican, the BBC's David Willey in Rome says.
Vatican Radio rejected his claims.
But debate about the record of wartime Pope Pius XII - who has been accused by some Jewish people of turning a blind eye to the Holocaust - has been reignited in recent weeks in Italy.
Pope Benedict has defended the actions of his predecessor, saying the pontiff spared no effort to try to save Jewish people during World War II.