Pope Francis has decreed that all Catholic priests and nuns must report sexual abuse and its cover-up to church authorities, including wrongs committed by bishops and cardinals.

His groundbreaking edict promises protection for whistleblowers and requires all dioceses to have a system in place to receive claims confidentially.

The new law, which applies retroactively, could unleash a fresh wave of abuse allegations and revelations in the global church.

It is the latest move by the pontiff in his struggle to get on top of the issue of sexual abuse which has rocked the Catholic church over recent decades. Wave after wave of scandals have discredited the church, and critics have accused Francis of failing to act decisively to root out abuse and abusers.

The pope has previously highlighted a culture of “clericalism” in the church, in which priests, bishops and other church officials are regarded with excessive deference. As a result, survivors of abuse have often found their accounts dismissed and denials by clergy have been accepted without investigation.

The edict, unveiled by the Vatican on Thursday, makes it mandatory for more than 1m priests and nuns across the globe to inform church authorities when they learn or have “well-founded motives to believe” that sexual abuse of a minor or sexual misconduct with an adult has taken place. They are also required to report possession of child pornography, or if a superior has covered up any offences.

However, the church law does not require police to be notified. The Vatican has said that different countries’ legal systems make a universal reporting law impossible, and that imposing one could endanger the church in places where Catholics are a persecuted minority.

Cardinal Marc Ouellet, head of the Vatican’s Congregation for Bishops, said: “We have said for years that priests should follow certain strict rules, so why should bishops and other members of the church hierarchy be exempt?”

Charles Scicluna, an archbishop who is the Vatican’s top sex crimes investigator, said: “People must know that bishops are at the service of the people. They are not above the law, and if they do wrong, they must be reported.”

The move was welcomed by the head of the US bishops conference, which has faced repeated scandals. The edict was a “blessing that will empower the church everywhere to bring predators to justice no matter what rank they hold in the church,” said Cardinal Daniel DiNardo.

Under the law, the crimes that must be reported are: performing sexual acts with a minor or vulnerable person, forcing an adult “by violence or threat or through abuse of authority to perform or submit to sexual acts”, and the production, possession or distribution of child pornography. Cover-up is defined as “actions or omissions intended to interfere with or avoid” civil or canonical investigations.

Survivors reporting abuse must be welcomed, listened to and supported by the hierarchy, as well as offered spiritual, medical and psychological assistance, the edict said.

Survivors must be informed of the outcome of investigations if they request it. Campaigners have said that survivors have routinely been kept in the dark about how their claims were handled.

In February, Pope Francis summoned bishops from around the world to Rome for an unprecedented summit on clerical sexual abuse, at which he said survivors deserved “concrete and efficient measures” and not mere condemnations.

The summit took place shortly before Cardinal George Pell, until recently the third most senior figure at the Vatican, was sentence to six years in prison for the sexual abuse of minors in the 1990s. He was the most senior member of the Catholic church to be convicted and jailed for child sexual abuse.

In February, Theodore McCarrick, a former archbishop of Washington and a former cardinal, was defrocked after the Vatican found him guilty of sexually abusing minors.

In March, Cardinal Philippe Barbarin, the archbishop of Lyon, France, was given a six-month suspended prison sentence for failing to report to the authorities accusations made against a priest.

The church has also faced abuse scandals and revelations in Chile, Germany, the Netherlands and India over the past year.

In the document released on Thursday, Pope Francis said: “The crimes of sexual abuse offend Our Lord, cause physical, psychological and spiritual damage to the victims and harm the community of the faithful.

“In order that these phenomena, in all their forms, never happen again, a continuous and profound conversion of hearts is needed, attested by concrete and effective actions that involve everyone in the church, so that personal sanctity and moral commitment can contribute to promoting the full credibility of the gospel message and the effectiveness of the church’s mission.

“Even if so much has already been accomplished, we must continue to learn from the bitter lessons of the past, looking with hope towards the future.”

