VATICAN CITY — Pope Leo has issued a strong appeal to the Society of St Pius X (SSPX), a traditionalist Catholic group, urging it not to proceed with the consecration of four bishops without papal approval. In a letter released ahead of the planned ceremony in Switzerland, the Pope warned that such an action would cause a schism in the Church and described it as a “sin of extreme gravity.”

The SSPX, founded in 1970 by French Archbishop Marcel Lefebvre, rejects the reforms of the Second Vatican Council in the 1960s, particularly the introduction of the Mass in the vernacular. The group also advocates for the integration of religious principles into political life. It currently claims a membership of 751 priests, 264 seminarians, and approximately 250 nuns.

Pope Leo, elected last year, has made efforts to heal divisions with conservative Catholics that widened during the previous pontificate. Notably, he has celebrated the traditional Latin Mass favored by groups like the SSPX, which Pope Francis had restricted. However, the planned consecrations risk undermining these reconciliation efforts. The Pope’s letter emphasizes concern for the spiritual welfare of the faithful, cautioning that the act would deprive them of the lawful—and sometimes valid—reception of sacraments that are central to their faith.

Church law states that any bishop consecrated without the Pope’s permission incurs automatic excommunication for committing a schismatic act. In 1988, Lefebvre himself consecrated four bishops without papal consent, leading to excommunications that the Vatican lifted in 2009 as part of attempts to reintegrate the SSPX into the Church’s canonical structure. Despite this outreach, the SSPX currently maintains no official standing within the Church.

Responding to the Pope’s appeal, a representative of the SSPX expressed “great sadness” at not being understood by the pontiff but affirmed that the group would not change its plans. When asked about the risk of excommunication, the official stated they were not afraid and viewed their actions as serving a greater good despite the potential penalties.

Some Catholic commentators, such as conservative blogger Marco Tosatti, have argued that Pope Leo should have permitted the consecrations, suggesting a divergence of opinions within the broader Church community on how to engage with traditionalist factions.

The unfolding situation highlights ongoing tensions within Catholicism between efforts to maintain unity and the persistent challenges posed by groups seeking to uphold older traditions outside the official framework of the Church.