VATICAN CITY — The Vatican raised the possibility Saturday that the conclave to elect the next pope might start sooner than March 15, the earliest date possible under current rules that require a 15-20 day waiting period after the papacy becomes vacant.

Vatican spokesman The Rev. Federico Lombardi said that the Vatican rules on papal succession are open to interpretation and that "this is a question that people are discussing."

"It is possible that church authorities can prepare a proposal to be taken up by the cardinals on the first day after the papal vacancy" to move up the start of conclave, Lombardi said.