The oath-taking is being held in the Pauline Chapel at the Vatican for all those assigned to the upcoming conclave. They include clerics in support roles, including confessors speaking various languages. The cardinals themselves will take their oath on Wednesday in the Sistine Chapel, before they cast their first ballots.

Workers and clerics assisting the dozens of Catholic cardinals set to gather Wednesday to begin voting on the next pope had to swear to never reveal anything about the proceedings or else risk the Church’s gravest punishment: religious banishment. The employees took their oaths in the Papal Chapel.

Support staff for the cardinals who will elect Pope Francis' successor are taking an oath of secrecy on Monday before the conclave starts on Wednesday.

There are currently 135 cardinals who are under age 80 and eligible to vote in the conclave, hailing from 71 different countries in the most geographically diverse conclave in history. Already two have formally told the Holy See that they cannot attend for health reasons, bringing the number of men who will enter the Sistine Chapel down to 133.

All of the 133 cardinals expected to take part in the secret conclave to elect a new pope have arrived in Rome, the Vatican said on Monday, with the race to succeed Pope Francis seen as wide open. The conclave will start behind the closed,