§1. The following are removed from an ecclesiastical office by the law itself: 1/ a person who has lost the clerical state; 2/ a person who has publicly defected from the Catholic faith or from the communion of the Church; 3/ a cleric who has attempted marriage even if only civilly.
§2. The removal mentioned in nn. 2 and 3 can be enforced only if it is established by the declaration of a competent authority.
Source: Code of Canon Law (Vatican.va)