LONDON — Archbishop of Canterbury Justin Welby, the spiritual leader of the global Anglican church, resigned Tuesday after an investigation found that he failed to promptly report serial physical and sexual abuse by a volunteer at Christian summer camps.

Welby said in a statement that he was stepping down “in sorrow” and “having sought the gracious permission of His Majesty The King.” He said that exact timings would be decided at a later date since “it is my duty to honor my constitutional and church responsibilities.”

He had faced mounting calls to resign since the damning independent report was published last Thursday.

In his resignation letter, Welby acknowledged “personal and institutional responsibility” for “wrongly” believing that there wasn’t a need to make a formal report to police on the case in 2013.

The report found that from July 2013, the Church of England knew “at the highest level” about John Smyth, who sexually, psychologically and physically abused about 30 boys and young men in the United Kingdom and 85 in Africa over five decades.

The church should have “properly and effectively” reported Smyth to the relevant authorities, the report found.

Archbishop of York Stephen Cottrell, second only to the archbishop of Canterbury, said Welby’s resignation was “the right and honorable thing to do.”

“As a church, we continue to work towards and must achieve a more victim-centred and trauma-informed approach to safeguarding within the Church of England, and this must address the broader questions of culture and leadership,” he added in a statement.

A petition calling for Welby’s resignation, created by members of the national assembly of the Church of England, the General Synod, had reached over 13,000 signatures at the time of his announcement on Tuesday.

When asked if Welby should resign, British Prime Minister Keir Starmer said the matter was ultimately for the Church to address but he emphasized the “clearly horrific” allegations of abuse, adding that it was evident the victims had been “failed very, very badly.”