(ANSA) - Vatican City, August 29 - Pope Francis is "embittered" by a letter written by Carlo Maria Viganò, the former top Vatican diplomat in the United States, which said Francis should step down for allegedly covering up a top US bishop's sex abuse, his close collaborators told ANSA. The former Vatican diplomat said in the document that Pope Francis had protected the former Washington DC archbishop, Cardinal Theodore McCarrick, who is accused of sexually abusing young seminarians.

The pope is not considering resigning, however, the sources said. Viganò said he told Francis about McCarrick in 2013, saying he had been sanctioned by former pope Benedict XVI, but Francis did nothing about it.

Francis has said he will not dignify Viganò's allegations with a reply.

The case has pitted conservative critics of Francis against progressive supporters who say the traditionalists are "weaponising" child abuse to attack the pope's mercy-over-morals approach.

Viganò also claimed there was a powerful gay lobby in the Church he blamed for the abuse cover-ups, naming names.

