The Pope's ambassador to one of Europe's leading Catholic countries has hinted that the church should "acknowledge" gay partnerships.
The suggestion by Spain's Monsignor Manuel Monteiro de Castro represents a significant crack in the Vatican's resolute opposition to "evil and deviant" gay relationships.
The monsignor told a conference of Spanish bishops at the weekend: "The new political situation in which we are living in Spain sets new challenges in the spreading of the gospel and we must meet those challenges in an appropriate manner."
Departing from his prepared speech, the papal nuncio added that although the law in Spain, and many other countries, defined marriage as the union of a man and a woman, "there are other forms of cohabitation and it is good that they be recognised".
Although he insisted that same-sex unions could not be regarded as marriages, he implied that they were at least worthy of compassion.
"They are not the same as marriage," he said. "We will leave the term marriage for that which it has always referred to, and other arrangements should be given other names."
The nuncio said gay couples should be given access to certain civil rights, including those within the social security system.
The remarks were in sharp contrast to last year's Vatican guidelines that called on Catholics to campaign against the legalisation of gay relationships, calling them evil, deviant and a grave threat to society.
The document said: "There are absolutely no grounds for considering homosexual unions to be in any way similar or even remotely analogous to God's plan for marriage and family.
"Legal recognition of homosexual unions or placing them on the same level as marriage would mean not only the approval of deviant behaviour . . . but would also obscure basic values which belong to the common inheritance of humanity."