A firebrand conservative who became one of Pope Francis’ most ardent critics has been excommunicated by the Vatican.

Archbishop Carlo Maria Viganò, who once served as the Vatican’s ambassador to the U.S., was found guilty of schism. The Vatican’s doctrine office imposed the penalty after a meeting of its members on Thursday, a press statement said Friday.

The office cited Viganò’s “refusal to recognize and submit to the Supreme Pontiff, his rejection of communion with the members of the church subject to him and of the legitimacy and magisterial authority of the Second Vatican Council,” as its reasoning for the ruling.

Viganò, who retired in 2016 at age 75 and was the papal envoy in Washington from 2011-2026, convulsed the Holy See with accusations of sex abuse in 2018, calling on Francis to resign.

In an 11-page letter, Viganò claimed that in 2013 he told Francis of the allegations of sex abuse against former Cardinal Theodore McCarrick. But, he wrote, the pontiff ignored that, and allowed McCarrick to continue to serve the church for another five years publicly. He said the pope should resign and subsequently branded him a “false prophet” and a “servant of Satan.”

In the letter, Viganò also made a number of ideological claims and was critical of homosexuals within Church ranks. He did not offer any proof for his statements.

The Vatican rejected the accusation of a cover-up of sexual misconduct and last month summoned Viganò to answer charges of schism and denying the pope’s legitimacy.

Viganò, who regarded the accusations “as an honor,” said he refused to take part in the disciplinary proceedings because he did not accept the legitimacy of the institutions behind it.

“I do not recognize the authority of the tribunal that claims to judge me, nor of its Prefect, nor of the one who appointed him,” he said in a statement issued last week, referring to the head of the doctrinal office, Cardinal Victor Manuel Fernandez, and to Francis.

Viganò restated his rejection of Vatican Council II, calling it “the ideological, theological, moral and liturgical cancer of which the (Francis’) ‘synod church’ is the necessary metastasis.”

He had not yet commented on the Vatican’s ruling on Friday.

McCarrick, the ex-archbishop of Washington, D.C., was defrocked by Pope Francis in 2019 after an internal Vatican investigation found he sexually molested adults as well as children.