Stefano Gabbana, of DolceGabbana fame, has rounded on the Vatican for trying to stop Italian gay and lesbian people getting equal rights.
The designer, in an interview with newspaper La Stampa, argued that the Roman Catholic church is trying to fight against love itself.
Mr Gabbana was the sexual as well as design partner of Domenico Dolce for 19 years.
In 2005 they announced the end of their relationship.
The pair continue their internationally successful fashion collaboration.
Their Milan-based company is worth £350m and their brand is a household name.
44-year-old Mr Gabbana said that the Catholic hierarchy, “fights every day against those who in its opinion cast doubt on the traditional concept of the family.”
Italy is debating whether gay couples should get legal recognition after ministers in the leftist coalition government of Romano Prodi drafted a bill that would create a form of civil partnership.
The eleven political parties that form the coalition range from communists to greens, but with such a broad spectrum of opinion represented there have already been disagreements about the proposed new law.
“The de facto family should also be protected,” said Mr Gabbana. He also said he did not understand, “as a Catholic, the church’s fight against love.”
Pope Benedict XVI has been trenchant in his opposition to more rights for gay people. He claims that granting gay and lesbian couples legal protection and recognition is a threat to heterosexual marriage.
Earlier this month he called any form of union other than marriage, “dangerous and counterproductive.”
DolceGabbana’s designs are particularly popular with movie stars.
Ayumi Hamasaki, Isabella Rossellini, Mrs Guy Richie and Kylie Minogue are all customers of the design duo.
In February 2005, they announced the end of personal relationship.
“On a professional level, we are still together,” Domenico Dolce told Corriere della Sera newspaper at the time.
“We work together wonderfully well, we have a very strong understanding. What happens in the past is still there, it continues and will continue forever. We have a very strong love which ties us to each other.”