The ordination of women as Roman Catholic priests has been made a "crime against the faith" by the Vatican and subject to discipline by its watchdog.

The new rules issued Thursday put attempts at ordaining women among the "most serious crimes" alongside paedophilia and will be handled by investigators from the Congregation for the Doctrine of the Faith (CDF), considered the successor to the Inquisition. Women attempting to be priests, and those who try to ordain them, already faced automatic excommunication but the new decree enshrines the action as "a crime against sacraments".

The unexpected ruling follows the Pope's welcome to Anglican clergy dissatisfied with its General Synod attempts to compromise over calls for the ordination of women as bishops. Under current plans, the first women bishops could be ordained in the Anglican Church as soon as 2014.

A group of 70 disgruntled clergy met with a Catholic bishop on Saturday to discuss plans to defect to the Roman Catholic Church and hundreds are said to be poised for an exodus to Rome. Earlier this year three bishops travelled to the Vatican to talk over an offer made by Pope Benedict XVI inviting disillusioned Anglicans to convert to Catholicism, while still keeping tenets of their own faith.

Within the Roman Catholic Church itself there have been growing calls to allow women to become priests in the wake of the widespread paedophilia scandal. Women priests have been allowed in the Anglican Church since 1992.

But the Vatican made its stance clear Thursday by comparing such actions to child abuse crimes and issuing new rules for investigating both by the same disciplinary body.

Federico Lombardi, the Vatican spokesman, underscored how the ordination of women is "a crime against sacraments," while paedophilia should be considered a "crime against morals" and both would fall under the jurisdiction of the CDF.

The organization, which was once known as the Holy Office of the Inquisition, was previously headed by the current Pope when he was Cardinal Joseph Ratzinger.

The raft of new rules from the Vatican includes the fast-tracking of the investigation process of priests accused of child abuse. The CDF will accelerate investigations of paedophile priests and extend the statute of limitations by 10 years to 20 years after the victim's 18th birthday. It could defrock priests but would not be forced to hand over abusers to the civil courts.

"Clergy sex crimes must be reported to police and the Vatican must make this a binding policy that is uniformly enforced," said David Clohessy, an executive at The Survivors Network for those Abused by Priests. "Today's action doesn't do that."