The cardinals have met repeatedly this past week, sketching out the qualities of the person needed to face the huge challenge of leading the scandal-plagued church.

"The expectations of the new pope and his profile was a recurring theme in this morning's interventions by the cardinals," said Father Tom Rosica, the Vatican spokesman for the English-speaking media

Vatican-watchers say Italy's Angelo Scola and Brazil's Odilo Scherer are in pole position, but a host of other candidates from around the world have also been mentioned, leaving the secretive contest wide open.

"Last time around there was a man of stature, three or four times that of any other cardinal," French Cardinal Philippe Barbarin told reporters, in a reference to Joseph Ratzinger who was elected pope within 24 hours in 2005.

"That is not the case this time around. Therefore, the choice has to be made among one, two, three, four ... a dozen candidates. We still don't really know anything. We will have to wait for the results of the first ballot."

The 115 cardinal-electors from 48 countries will file into the Michelangelo-frescoed Sistine Chapel at 4.30 p.m. (10.30 a.m. ET) tomorrow and will hold an initial vote shortly afterwards.

"There is a dynamic that takes over once they're in the Sistine Chapel. The first vote kind of lays out the names. We will have a pope by the end of the week," said Father Rosica.