Up to four ballots are held each day. If no candidate receives the required two-thirds of the votes by the third day, a one-day break for prayer is required.
According to the daily La Repubblica, Cardinal Angelo Scola, the 71-year-old archbishop of Milan, Italy, has already gained the support of some 40 cardinals, being more than half way to reach the 77 needed for the required two-thirds majority in the conclave.
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It's not the first time that the Italian cardinal appears as a papal candidate. A top-secret, leaked Vatican document, published last year by the Italian daily Il Fatto Quotidiano, revealed that Benedict XVI was secretly working on his succession, having chosen Scola as the next Pope.
Seen as an outsider by the Roman Curia, the administration assisting the Pope, Scola is supported by a group of cardinals referred as "riformisti" or reformers, which include Austrian Cardinal Christoph Schonborn and US Cardinals Timothy Dolan and Sean O'Malley.
Both American cardinals are considered papabili, strong candidates for the papal throne.