Pope Benedict XVI on Monday accepted the immediate resignation of Britain’s highest-ranking Roman Catholic cleric, effectively forcing Cardinal Keith O’Brien to step down two days after allegations surfaced publicly that he had engaged in inappropriate behavior with priests.

   The latest scandal to engulf the church involves one of its most strident conservatives and influential clerics, and comes just weeks before the conclave to select a successor to Benedict, who unexpectedly announced his retirement on Feb. 11.

Britain’s Observer newspaper reported Saturday that one of O’Brien’s alleged victims said O’Brien had started a “relationship” with him in the 1980s that resulted in the need for long-term counseling. Another of the men, according to the newspaper, said O’Brien had initiated “inappropriate contact” during nightly prayers.

O’Brien, 74, himself was scheduled to retire next month and had presented the pope with a resignation letter in November. He has denied the allegations against him and retained legal counsel. But Benedict, after being informed of the allegations on Sunday, decided to accelerate O’Brien’s exit.

In a statement, O’Brien said he would not attend the conclave to select a new pope, as he had been slated to do, but instead will “pray with them and for them that, enlightened by the Holy Spirit, they will make the correct choice for the future good of the Church.”

“I have valued the opportunity of serving the people of Scotland and overseas in various ways since becoming a priest,” O’Brien, who was head of the church in Scotland, said in the statement. “Looking back over my years of ministry: For any good I have been able to do, I thank God. For any failures, I apologize to all whom I have offended.”

In a news conference a short time later at the Vatican, church officials insisted that O’Brien decided on his own not to participate in the conclave. That represented a marked change from 2005, when the Vatican fully expected Cardinal Bernard Law, the disgraced archbishop of Boston who was then in the eye of the sex abuse storm, to attend the conclave at which Benedict was ultimately selected.

“The cardinal can say what he wants to say,” said Vatican spokesman Rev. Federico Lombardi on Monday morning. Added his colleague, Rev. Tom Rosica: “Nothing has been mentioned about his participation in the conclave.”

John Allen, a leading Vatican observer and correspondent for the National Catholic Reporter, called their remarks “a clear shift in rhetoric.”

“In 2005, the Vatican stated that it was a clear duty for cardinals to participate in the conclave,” Allen said. “It appears that they are now shifting the burden for making that decision onto the cardinals themselves.”

The nuance could be interpreted as evidence that the days of the church circling the wagons around prelates stained with allegations of wrongdoing in sex abuse cases are over — or at least changing. Now, in contrast, such clerics appear to be at risk of finding themselves under the wagon’s wheels.

At the news conference, Vatican officials introduced Benedict’s amendment to Vatican rules governing papal succession. The new Vatican norms, issued in an edict known as a Motu Proprio, stipulated that the two-thirds threshold required to elect a pope should take into account only those voting cardinals present at the conclave, not the entire voting college — of which O’Brien, for example, remains a member.

The Vatican said that a cardinal who chooses not to participate needs to officially notify the Holy See of that decision. In other words, a media statement like the one O’Brien issued Monday will not suffice.

The officials also relayed details of Benedict’s meeting earlier Monday with cardinals he had appointed to investigate a papal letter-leaking scandal that cast a shadow over his last year in office. The dossier on the so-called VatiLeaks scandal, prepared by three octogenarian cardinals — Julian Herranz, Jozef Tomko and Salvatore De Giorgi — has prompted months of speculation, followed by strong denials by the Vatican in recent days of thinly sourced reports in the Italian press about what trio allegedly discovered.

On Monday morning, Benedict dissolved the committee and “expressed satisfaction for the results of the investigation,” according to a Vatican statement read at the press conference. “Their work made it possible to detect, given the limitations and imperfections of the human factor of every institution, the generosity and dedication of those who work with uprightness and generosity in the Holy See at the service of the mission entrusted by Christ to the Roman Pontiff,” the statement added. “The Holy Father has decided that the acts of this investigation, known only to himself, remain solely at the disposition of the new pope.”

Lombardi, once again, spoke of the stubborn scandal’s “conclusion.”

While the report remains for the pope and his successor’s eyes only, the three cardinals are, Rosica said, “free to share ideas or answer questions” about their investigation, with the understanding that the information could prove germane to cardinals selecting the next pope.

Perhaps the most coveted piece of information around the Vatican — the start date of the conclave — was not announced at the news conference.

Instead, officials explained that Benedict’s edict essentially puts the burden on the College of Cardinals to select the date on which they will close of the doors of the Sistine Chapel behind them and begin a series of discussions that will not end until a new pope is named.

“It can’t happen before the first of March because they won’t meet before the first of March,” Lombardi said of the cardinals. “And they probably won’t decide during their first meeting.”

The scandal involving O’Brien could cast a shadow over the church’s moral authority in Europe — the continent where the church is losing the most ground globally. O’Brien had emerged as a leading voice in Britain against homosexuality. Last year, O’Brien decried the campaign to legalize same-sex marriage in Britain as a “grotesque subversion of a universally accepted human right.”

Allies of O’Brien, however, were quick to defend him, saying judgment should be reserved until a full airing of the facts emerged.

The Observer’s report did not specify the extent to which the encounters that O’Brien allegedly initiated were consensual or ultimately resulted in sexual acts. None of the four men were named, and they could not be independently reached.

The Observer quoted one man who said he was a 20-year-old seminarian in the 1980s when first approached by O’Brien. After O’Brien was promoted to bishop, the unidentified man said, he left the priesthood “to preserve my integrity.”

“You have to understand the relationship between a bishop and a priest,” the paper quoted the man as saying. “At your ordination, you take a vow to be obedient to him. He’s more than your boss, more than the CEO of your company. He has immense power over you. . . . He can move you, freeze you out, bring you into the fold. . . . He controls every aspect of your life.”

The paper said the men recently reported their allegations to the Vatican emissary in London with the aid of an intermediary from their diocese in the week before the pope’s resignation. The move appeared pegged to O’Brien’s planned retirement. The men were demanding O’Brien’s immediate resignation and apparently went public in an effort to block the cardinal from taking part in the papal conclave.

The allegations surfaced at a time when the papal conclave is being cast in an unwelcome spotlight. Lay groups are orchestrating a campaign to prevent Cardinal Roger Mahony, the former archbishop of Los Angeles, from attending the conclave to choose the next pope. Mahony was stripped of his duties last month over allegations that he shielded pedophilic priests in the 1980s. Victims’ rights groups were quick to demand swift action from the Vatican on the allegations against O’Brien.

“It doesn’t matter that the offenses may have been years ago or that the victims may have technically been adults,” said Barbara Blaine, a spokeswoman for the U.S.-based Survivors Network of Those Abused by Priests. “What matters is that, once again, a shrewd, high-ranking Catholic official misused his role and status and power to harm and selfishly take advantage of vulnerable teens and young men.”

Horowitz reported from Rome. Eliza Mackintosh in London and Stefano Pitrelli in Rome contributed to this report.