The Vatican on Saturday fired a senior priest who publicly came out as gay on the eve of a synod of bishops at which the issue of the Church's stance on homosexuality.

In a statement, a spokesman for Pope Francis said Polish priest Krzystof Charamsa's action had been "very serious and irresponsible", and that he would be automatically kicked out of his post as a theologian in the Vatican.

Flanked by his Catalan boyfriend and sporting his priest's collar, Charamsa told a news conference in Rome he had been compelled to speak out against the hypocrisy and paranoia that he says shapes the Church's attitude to sexual minorities.

While appearing resigned to the fact that his life as a priest is over, he said: "I'm out of the closet and I'm very happy about that."

Visibly moved at times but always smiling, the 43-year-old added in Italian: "I want to be an advocate for all sexual minorities and their families who have suffered in silence."

In an indication that Charamsa had planned the move for some time, he presented a 10-point "liberation manifesto" against "institutionalized homophobia in the Church", which he said particularly oppressed the gay men who, according to him, make up the majority of priests.

He also revealed plans for a book about his 12 years at the heart of a Vatican bureaucracy only just recovering from a scandal under previous pope Benedict XVI over the influence of a "gay lobby" among senior clergy.

"I dedicate my coming out to all gay priests," Charamsa said. "I wish them happiness even if I know that most of them will not have the courage to make the gesture I have made today."

"To my Church, I want to say that I reject and I denounce the current atmosphere of exasperating homophobia. Open your eyes to the suffering of gay people, to their desire for love."

Charamsa timed his announcement for maximum media impact, coming as it did on the eve of a synod that is the second and final round of a review of Catholic teaching on the family.

Although the issue of homosexuality forms only a tiny part of the synod's agenda, it has dominated the run-up to the three-week meeting and become a lightning rod for a broader debate between reformists and conservatives in the Church.

Catholic attitudes to sexuality were already making headlines this weekend after the Vatican confirmed that Francis had hugged an old gay friend and met his partner during his recent visit to the United States.

The highly symbolic gesture, indicative of Francis's personally tolerant attitude towards gays, came a day before he met prominent gay marriage opponent Kim Davis — another private encounter that the Vatican said did not indicate support for her stance.

Al Jazeera and Agence France-Presse