Pope John Paul II has again publicly opposed same-sex marriage. In a speech to the new Canadian Ambassador to the Holy See, Donald Smith, the pope said on Saturday that legal guarantees "cannot be applied to unions between persons of the same sex without creating a false understanding of the nature of marriage."

In the statement released by the Vatican, the Pope praised Canada's contributions to the international community and the country's tolerance of ethnic groups, before focusing on the definition of marriage.

"The institution of marriage necessarily entails the complementarily of husbands and wives who participate in God's creative activity through the raising of children."

"Spouses thereby ensure the survival of society and culture, and rightly deserve specific and categorical legal recognition by the State," said the pontiff.

"Any attempts to change the meaning of the word spouse contradict right reason: legal guarantees, analogous to those granted to marriage, cannot be applied to unions between persons of the same sex without creating a false understanding of the nature of marriage."

In past months, the pope has consistently urged authorities to stop approving gay marriages, saying that they degrade the true sense of marriage between a man and a woman.

While the Canadian provinces of Quebec, Ontario and British Columbia already recognise same-sex marriage, it is believed that the Roman Catholic leadership is trying to apply public pressure on Prime Minister Paul Martin who is a Catholic and over the same-sex marriage question on Ottawa.