The former top Vatican diplomat in the United States wrote an explosive letter claiming Pope Francis knew all about the sex abuse carried out by a top American cardinal for years before the prelate resigned over the summer. The 11-page letter from Archbishop Carlo Maria Vigano, who was recalled from his Washington post in 2016, seemed to be timed to cause maximum damage to the pontiff. The release of the letter came as Francis was visiting Ireland and begged “the Lord’s forgiveness” for child abuse.

Vigano’s 7,000-word letter, which was published by several conservative Catholic news outlets, accuses Francis of being complicit in covering up the accusations against Cardinal Theodore McCarrick. Vigano claims Benedict XVI, Francis’ predecessor, had already disciplined McCarrick for his abuse of seminarians and priests. Vigano said he told Francis about this but the pope proceeded to rehabilitate McCarrick. “Pope Francis has repeatedly asked for total transparency in the Church,” Vigano writes. “He must honestly state when he first learned about the crimes committed by McCarrick, who abused his authority with seminarians and priests. In any case, the Pope learned about it from me on June 23, 2013 and continued to cover him.”

Francis isn’t alone in failing to take action, Vigano writes, noting that warnings about McCarrick’s conduct made it to the Vatican starting in 2000. Pope Benedict XVI eventually sanctioned McCarrick to a lifetime of penance and prayer in 2009 or 2010.

When Vigano met with Francis shortly after he became pope, they talked about McCarrick. Vigano claims he told Francis: “Holy Father, I don’t know if you know Cardinal McCarrick, but if you ask the Congregation of Bishops, there is a dossier this thick about him. He corrupted generations of seminarians and priests, and Pope Benedict ordered him to withdraw to a life of prayer and penance.” That is why Vigano claims he was shocked when McCarrick started traveling on missions for the church. McCarrick became the first U.S. cardinal in history to resign last month following claims that he sexually abused boys.

Vigano’s letter ends with a call for Francis’ resignation. “In this extremely dramatic moment for the universal Church, he must acknowledge his mistakes and, in keeping with the proclaimed principle of zero tolerance, Pope Francis must be the first to set a good example to Cardinals and Bishops who covered up McCarrick’s abuses and resign along with all of them,” he wrote.

Vigano is hardly a neutral source considering his known hatred for Francis. After returning to Rome, Vigano “has run with a crowd of traditionalist Catholics deeply critical of Pope Francis and recently attended a raucous meeting of anti-Francis prelates and faithful in the basement of a Rome hotel,” reports the New York Times.