"Who has more innocent deaths on their conscience, Totò Riina or Emma Bonino?"

 An Italian priest has sparked outrage after comparing a respected lawmaker who campaigned for abortion rights to the most notorious mafioso in the country's history.

The priest – based in Bologna, central Italy – took to Facebook to ask his virtual friends who they think had killed more people between former foreign minister Emma Bonino or brutal mobster Salvatore 'Toto' Riina, known in the country as the "beast" and the "boss of all bosses".

"Who has more innocent [deaths] on their conscience, Totò Riina or Emma Bonino? " wrote father Francesco Pieri , according to local newspaper Il Resto del Carlino. "Morally, there is no difference," he continued.

Bonino has been a prominent campaigner for abortion rights in Italy, where the practice is legal within the first 90 days of pregnancy. It is allowed only if the fetus has a genetic deficiency or to preserve the physical and mental health of the mother.

The issue is, however, divisive, and doctors can refuse to perform an abortion – even when the legal requirements are met – on religious grounds. Those who object to the practice are referred to as "conscientious objectors".

Bonino, a feminist and former member of Italy's Radical party, was jailed for three weeks in 1975 after demonstrating for abortion rights. She continued to campaign on the issue until the country legalised the practice following a referendum in 1978.

Riina, who died on 17 November at the age of 87, was serving 26 life sentences as the mastermind of a bloody strategy to assassinate Italian prosecutors and law enforcement who were attempting to bring down the Sicilian mafia syndicate Cosa Nostra.

The man, once the head of Cosa Nostra, was a brutal crime boss who waged a bloody war against the Italian state. High-profile killings include those of military police general Carlo Alberto Dalla Chiesa and anti-mafia prosecutors Giovanni Falcone and Paolo Borsellino.