The Vatican has ruled the Catholic church does not have the power to bless same-sex unions.
Its doctrinal office, the Congregation for the Doctrine of the Faith (CDF), issued the ruling on Monday in response to moves in some parishes to offer to bless such unions.
But it found that moves to bless homosexual couples, who ask for some type of religious recognition of their union, cannot "be considered licit" - or lawful.
The CDF said Pope Francis was informed and "gave his assent" to the publication.
In its ruling, the CDF said in order to conform with the "nature of sacramentals", "only those realities which are in themselves ordered to serve those ends are congruent with the essence of the blessing imparted by the church."
"For this reason, it is not licit to impart a blessing on relationships, or partnerships, even stable, that involve sexual activity outside of marriage (ie outside the indissoluble union of a man and a woman open in itself to the transmission of life), as is the case of the unions between persons of the same sex".
Pope Francis previous comments
It added that while there are "positive elements" in such relationships - "which are in themselves to be valued and appreciated" - these cannot justify or render them "legitimate objects of an ecclesial blessing".
However the ruling noted that this does not prevent blessings being given to "individual persons with homosexual inclinations".
In October last year, Pope Francis said homosexual partnerships should be protected by civil union laws.
He said: "Homosexual people have a right to be in a family. They are children of God and have a right to a family. Nobody should be thrown out or be made miserable over it".
"What we have to create is a civil union law. That way they are legally covered. I stood up for that".
While back in 2014, comments by the Pope were hailed as a 'critical first step' by then- chief commissioner designate of the Irish Human Rights and Equality Commission, Emily Logan.
A report following a round of bishops' discussions on various issues concluded that gay people had 'gifts and qualities' to offer Catholicism.
It was a seen as a departure from the Vatican sentiment on the area before the election of Pope Francis.
While former President Mary McAleese has previously described the Catholic Church's teaching on homosexuality as "evil."
Speaking in 2018, she said: "The Catholic church's teaching on homosexuality is in my view evil.
"It conduces to homophobia. homophobia is evil; it ruins people’s lives, it has ruined families lives, it has caused people to commit suicide, it has caused people to live in dark shadows, so unsure of themselves."
Highlighting the experiences of her son Justin McAleese, a married gay man, she said the church has a lot to answer for.
"He used to rush out in the morning; he was the first out to mass, loved being an altar boy, loved the church; loved the magic and the mystique of it.
"And then to discover when he was in his teens that that same church has a view on him which is inimical to the way God made him and to retreat into the shadows of self doubt; of misery, of being really frightened.
"That is un-Christian; that is worse than un-charitable in my view; that has to stop. The only person who can actually stop that strangely enough is the Pope", she added.