The Vatican has launched a global campaign against gay marriages, warning Catholic politicians that support of same-sex unions is "gravely immoral."
The Vatican issued a 12-page set of guidelines with the approval of Pope John Paul II in a bid to stem the increase in laws granting legal rights to homosexual unions in Europe and North America.
"Marriage exists solely between a man and woman ... Marriage is holy, while homosexual acts go against the natural moral law," the 12-page document by the Vatican's Congregation for the Doctrine of the Faith said Thursday.
"Legal recognition of homosexual unions or placing them on the same level as marriage would mean not only the approval of deviant behavior ... but would also obscure basic values which belong to the common inheritance of humanity."
The document, which has been two years in the making, calls on Roman Catholic lawmakers to vote against bills legalizing gay marriage, and where they already exist, work towards repealing them.
It does not list strictures, such as excommunication, against those who rebuff the church on the matter.
"To vote in favor of a law so harmful to the common good is gravely immoral," the document said.
Countries which already have relaxed laws to same sex unions include the Netherlands and Belgium.
It is the second time this year the Vatican has formally issued the instruction, and mirrors similar comments made by U.S. President George W. Bush Wednesday.
The president said: "I believe marriage is between a man and a woman, and I think we ought to codify that one way or another."
Banners reading 'No God, Atheism and Liberty', 'Democracy Yes, Theocracy No' and 'Free the laws of the State from the taboos of religion' are held by protesters and Radical party members outside St. Peter's Basilica, at the Vatican, Thursday, July 31, 2003.
The Vatican launched a global campaign against gay marriages Thursday, warning Catholic politicians that support of same-sex unions was 'gravely immoral' and urging non-Catholics to join the offensive.
Gay marriage is forbidden in the U.S. though the question of gay marriage has moved to the foreground of American politics after a Supreme Court decision in June which struck down state laws banning sodomy.
One state, Vermont, allows same-sex civil unions, and Massachusetts' top court is set to rule on the issue soon.
Canada courts have recently recognized gay marriages heralding hundreds to tie the knot in Ontario and British Columbia.
The Vatican's document - "Considerations Regarding Proposals to Give Legal Recognition to Unions Between Homosexual Persons" - also denounces gay couples adopting children.
"Allowing children to be adopted by persons living in such (homosexual) unions would actually mean doing violence to these children ... (placing) them in an environment that is not conducive to their full human development."
In Europe, the Netherlands has recognized registered gay partnerships since 1998 with Belgium following suit in January this year.
The Netherlands also passed laws in December 2000 allowing same-sex couples to marry and adopt children.
Several other countries have given gays rights just short of those enjoyed by heterosexual married couples.