The court ruling dealt a resounding legal defeat to Prime Minister Mariano Rajoy's right-leaning party, which lodged its objection just three months after the law was passed in July 2005. The party, then in opposition, had contested the use of the word "marriage" to describe a union between a same-sex couple.
Justice Minister Alberto Ruiz Gallardón conceded that the court's published ruling had established a doctrine that was "binding" and his party would therefore make no changes to the legislation. The legal victory reinforces then prime minister Jose Luis Rodríguez Zapatero's tradition-shattering reform, one of a string of legal changes he introduced to put Spain on the forefront of progressive social change.
In its ruling, the top court simply said it "rejected the appeal" by more than 50 members of the Popular Party who had argued the law was not constitutional. A full copy of the decision and arguments, backed by eight of the 12 judges but with three against and one abstaining, is to be released in the days ahead, it said.
Hours ahead of the decision, Rajoy said his party had objected in particular to the use of the word "marriage". "We appealed not because the union of two people of the same sex would have legal effects, that did not matter to us," he told Cope radio. "The only thing we appealed was the name, that is to say the word 'marriage' was the reason for the appeal."
The Spanish court decision comes just as neighbouring France's Socialist government is about to propose gay marriage legislation, which has been hotly opposed by the Church and some conservatives. Spain's gay marriage law, which also lets homosexual couples adopt children, has allowed as many as 22,000 gay couples to wed, according to a national federation of gays, lesbians, transsexuals and bisexuals. When the legislation was passed seven years ago, Spain became only the third member of the European Union after Belgium and the Netherlands to allow same-sex weddings.