Pope Leo XIV has issued a plea to a breakaway group of traditionalist Catholics to call off its planned consecrations of new bishops without his consent. In a letter released Tuesday, Leo called the move a schismatic act and a “sin of extreme gravity.” Leo's letter to the Rev. Davide Pagliarani, the superior of the Society of St. Pius X, was issued a day before the planned consecrations of four new bishops at the society’s seminary in Econe, Switzerland. Under church law, the consecrations constitute a schismatic act and incur automatic excommunication for the four bishops and the bishop who consecrates them.