The Congregation of the Doctrine of the Faith said yesterday: "These variations arise from so-called feminist theology and are an attempt to avoid using the words Father and Son, which are held to be chauvinistic."

Instead, it said that the traditional form of "Father, Son and Holy Ghost" had to be respected.

The alternative phrases originated in North America and started to become popular only in the past few years.

The new phrases are particularly popular in the Church of England. It was recently reported that guidelines to bishops and priests advised them to avoid "uncritical use of masculine imagery".

The Catholic Church and the Church of England are split over feminist issues.

The Archbishop of Canterbury, Dr Rowan Williams, and the Pope, met in Rome last year, but admitted that the ordination of women priests was a "serious obstacle" to closer ties.

The Pope, who wrote the latest ruling, has been a strong opponent of feminism in the Catholic Church.

In his book, The Ratzinger Report, he wrote: "I am, in fact, convinced that what feminism promotes in its radical form is no longer the Christianity that we know; it is another religion."

Rosemary Radford Ruether, a professor of feminist theology at the Graduate Theological Union in California, said that among "liberal" Catholics, the Pope "is not our Pope".

The Vatican said anyone baptised under the feminist terms could invalidate their marriage. Cardinal Urbano Navarrete, who wrote a formal commentary on yesterday's ruling, gave warning that anyone who attempted to baptise someone with a gender-neutral form would be penalised. "It is seriously illegitimate and unjust," he said.

Monsignor Antonio Miralles, a professor at the Pontifical Holy Cross University, said the new baptism "subverts faith in the Trinity" because it does not make the relationship between the three persons clear. "God is eternally Father in relation to His only begotten Son, who is not eternally Son except in relation to the Father."

Meanwhile, the Pope also spoke out against gay marriage and abortion before his first trip to the United States before Easter. He praised Americans who respected the "institution of marriage, acknowledged as a stable union between a man and a woman".

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