A US Catholic group has called for an American cardinal accused of covering up sexual abuse by priests not to take part in electing a new pope, saying he would taint the new pontiff with the same scandal that dogged Pope Benedict XVI.

As of Tuesday, the group Catholics United had gathered more than 5,000 signatures against Cardinal Roger Mahony, archbishop of Los Angeles until 2011.

"Please do not bring further scandal to our Church that has already been rocked by the sex abuse crisis by attending the

Papal Conclave. You have been disciplined and you have lost your ability to have a voice within our Church," said the petition from the Washington-based group.

The campaign gained momentum when Italy's best-selling magazine Famiglia Cristiana - "Christian Family" - asked its readers whether Mahony should attend the conclave that elects a successor to Benedict next month.

The overwhelming answer to the popular weekly magazine's survey was "no".

"No, he must not participate, for the good of the Church," wrote Superemme, in a typical response among hundreds on Famiglia Cristiana's website.

'Conscience decision'

In an interview with Al Jazeera, Vatican journalist Alessandro Speciale said it is up to Mahony to examine his "conscience" and decide if he wants to participate in the conclave.

"The Vatican constitution that regulates the election of a new pope is very clear that no one who has the right to elect the pope can be excluded from his right," Speciale said. "The church is very steep in its tradition."

But Speciale also acknowledged that it was "disastrous" for the church hierarchy to have to answer to the scandal at a critical time, when it is choosing a new leader.

As archbishop of Los Angeles from 1985, Mahony worked to send priests known to be abusers out of state to shield them from law enforcement scrutiny in the 1980s, according to church files unsealed under a US court order last month.

Although his successor, Archbishop Jose Gomez, removed him from all public and administrative duties, Mahony has announced his intention to fly to Rome where he would be among 117 cardinals allowed into the Vatican's Sistine Chapel to vote for the next leader of the world's 1.2 billion Catholics.

Last week, Benedict, 85, became the first pope in centuries to abdicate rather than die in office, saying effects of old age meant he was unable to complete his ministry.

His eight-year reign will be remembered by many for the child sex abuse scandal in Europe and the United States - most of which took place in the 1980s but which came to light more recently.

In his former position as head of the Congregation for the Doctrine of the Faith, critics say he was ultimately responsible for the way child abuse by priests was covered up for decades in order to preserve the Church's reputation.

The Vatican denies this, saying he enacted procedures to shield children from abuse in the future and to screen out potential paedophiles from entering the priesthood in the first place.