VATICAN CITY (AFP) ― Pope Benedict XVI issued a decree on Monday allowing cardinals to bring forward a conclave to elect his successor, as the resignation of a top cardinal and deepening intrigue in the Vatican clouded the run-up to the vote.

“I leave the College of Cardinals the possibility to bring forward the start of the conclave once all cardinals are present,” said the pope, who steps down on Thursday.

The conclave is traditionally held between 15 and 20 days after the papal seat becomes vacant although that period normally includes nine days of mourning for a deceased pope.

A climate of intrigue and scandal has gripped the Vatican at the approach of the conclave, accentuated by the resignation announced Monday of British Cardinal Keith O’Brien over allegations of inappropriate behavior.

O’Brien, who as archbishop of St. Andrews and Edinburgh was leader of the Catholic Church in Scotland, denies the allegations that he made sexual advances towards priests in the 1980s.

But O’Brien, Britain’s most senior Roman Catholic cleric, said: “For any failures, I apologize to all whom I have offended.”

He added that he would not take part in the conclave in order to avoid the media attention he would attract.

Vatican spokesman Federico Lombardi said cardinals who will kick off meetings to discuss the upcoming conclave on Friday could settle on a date “in the very first days of March.”

The Vatican revealed meanwhile that a report into a series of damaging leaks of confidential papal papers last year had pointed up “imperfections” in the Catholic hierarchy.

The report “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,” a Vatican statement said.

“The Holy Father has decided that the documents, which only he has seen, will be exclusively available to his successor,” Lombardi told a press conference.

Italy’s Panorama news weekly and the Repubblica daily had said Thursday that the cardinals’ December report to the pope contained allegations of corruption and of attempts to blackmail gay Vatican clergy, as well as favoritism based on gay relationships.

They submitted the report to Benedict just before the pope pardoned his former butler Paolo Gabriele, who had been jailed for leaking the papal memos in the so-called “Vatileaks” scandal, while banishing him from the Vatican.

Suspicions linger that more people were involved.

Lombardi denied Italian media reports suggesting that the cardinals set to elect the next pope would be given access to the Vatileaks report.

But he said the report’s authors might discuss its contents with the cardinal electors “without making the text available to them.”

It is normal for “the cardinals to advise each other and help each other to understand situations” and therefore the investigators could share “useful elements for evaluation,” Lombardi said, adding that the cardinals would be sworn to secrecy over such discussions.

The three cardinals -- all over 80 and thus not entitled to vote in the conclave -- questioned dozens of Vatican officials, both laypeople and clergy, in parallel with a police probe.

Benedict, 85, cited his age as the main factor in his nearly unprecedented decision to resign, but observers said Vatileaks may have been the last straw in a scandal-ridden papacy.

Four members of the conclave, to number 115 following O’Brien’s withdrawal, are associated with the paedophile priest scandals that have dominated Benedict’s eight years on the papal throne.

The pope is due to hold his final public farewell in St Peter’s Square on Wednesday before stepping down on Thursday as leader of the world’s 1.2 billion Catholics.