VATICAN CITY — There can be no reprieve for divorced and remarried Catholics, the Vatican told bishops around the world Friday.

Stiffly reaffirming a traditional teaching that is disregarded by millions, the Vatican said that Roman Catholics who break their marriage vows remain within the church but cannot receive Communion even if they feel able to do so with a clear conscience.

Cardinal Joseph Ratzinger, the conservator of Vatican orthodoxy as head of the Congregation of the Doctrine of the Faith, signed the letter to bishops issued Friday, but a postscript said it had been approved by Pope John Paul II, who ordered its publication.

Vatican sources said the letter was a riposte to three liberal German bishops who said publicly last year that divorced and remarried Catholics could follow their consciences in deciding whether to take Communion.

That is not allowed, Ratzinger says, deploring "the mistaken conviction" that a divorced and remarried Catholic may decide on the basis of personal conviction about his or her worthiness for Communion.

"Such a position is inadmissible," the Ratzinger letter says. Exceptions would be if a first marriage was canonically annulled, or the divorced and remarried Catholic repented and abstained from sex with the new spouse, according to the letter.

Issued during a Vatican synod on religious life, the letter can only exacerbate sharp differences of opinion on bedroom issues and questions of conscience between the Vatican and Catholics in the United States and other First World countries.

Just as many divorced and remarried Catholics take Communion, so do an overwhelming majority of American Catholics tell pollsters that they violate church prohibition of artificial birth control.

To receive the Eucharist, which Catholics regard as the body of Christ, is the essence of full participation at Mass. Still, the Ratzinger letter should not alienate divorced Catholics, according to the president of the U.S. National Conference of Catholic Bishops.

Rather, the letter reflects "constant teaching" of the church. It is not "a punishment or a discrimination against those who are divorced and remarried," says a statement issued by Archbishop William Keeler of Baltimore.

Despite Keeler's official remarks, protests are expected from rank-and-file Catholics.

"I'm standing by for the onslaught," said one official with the Catholic bishops conference in Washington.