They said the prophetic warnings contained within "Humane Vitae," (Of Human Life) published by Blessed Pope Paul VI July 25 1968, have proved to be accurate.

"We propose discovering anew the message of 'Humanae Vitae,' not only in fidelity to the Gospel, but as a key to the healing and true development of our society," they said in the statement sent to the London-based Catholic Herald magazine June 14, ahead of the 50th anniversary of the encyclical's publication.

The statement said "Humanae Vitae" represented a "re-affirmation of central aspects of the church's traditional teaching on human sexuality," including that the conjugal act was "always open to procreation and always unitive."

"Humanae Vitae predicted that if artificial contraception became widespread and commonly accepted by society, then we would lose our proper understanding of marriage, the family, the dignity of the child and of women, and even a proper appreciation of our bodies and the gift of male and female," the statement said.

"The Holy Father warned that governments would begin to utilize coercive methods to control what is most private and intimate," it said.

"At the time of the publication of 'Humanae Vitae,' many rejected its message and its warnings," it continued. "Many found the teaching that the use of contraception was in all cases 'absolutely excluded' and 'intrinsically wrong' difficult to accept and challenging to proclaim."

But 50 years after its publication, "so much has unfolded in our society that has been to the detriment of human life and love," the statement said.

"Many have come to appreciate again the wisdom of the church's teaching," it said, adding that signers hoped to affirm "the noble vision of procreative love as the Catholic Church has always taught and understood it."

"We believe a proper 'human ecology,' a rediscovery of the way of nature and respect for human dignity is essential for the future of our people, Catholic and non-Catholic alike," it said.

The 462 signatories represent about one in 13 of all of the priests in England, Wales and Scotland.

"Humanae Vitae" was hugely controversial when issued by Blessed Paul VI, who will be canonized in October, not least because it overrode the initial proposals of a papal commission drafted to re-examine teaching on birth control.

The document clearly asserted the teaching of the church against artificial contraception at the height of the sexual revolution.

Blessed Paul warned the faithful that breaking the unitive and procreative aspects of the conjugal act would "lead to the way being wide open to marital infidelity and a general lowering of moral standards."

He said women would be treated as sexual objects even by their own husbands and that governments would seek to solve social problems by imposing the use of contraception "on everyone."

The pope appealed to scientists to develop methods of fertility regulation consistent with the principles of Catholic teaching, and natural family planning methods have since been devised.