MEXICO CITY — Mexico’s Supreme Court voted Wednesday to allow a group of activists to legally grow and smoke marijuana, marking the first loosening of drug prohibitions in the country and fueling debate about a crop that is at the center of a decade of violence.

The ruling deemed unconstitutional aspects of the national health law that prohibit marijuana use. Although the decision allows only the plaintiffs to consume the drug, activists said it sets a precedent that could accelerate efforts to permit recreational or medicinal use of marijuana.

“Absolute prohibition is excessive and doesn’t protect the right to health,” Justice Olga Sánchez Cordero said.

The growing debate on marijuana use is an important development for Mexico, one of the world’s biggest producers of the drug. The country has endured brutal losses during its drug war yet remained largely opposed to legalization, even as several U.S. jurisdictions have moved forward with laws allowing use of cannabis.

Across Latin America, governments have been rejecting the Washington-driven hard line in the drug war in favor of decriminalization – a recognition that years of violent struggle have failed to stem the flow of narcotics into the U.S. But Mexico has held on to its conservative drug laws .

As news spread that the Supreme Court was considering the case, some public officials spoke out in favor of various forms of legalization. Mayor Miguel Ángel Mancera said that Mexico City was ready for medicinal marijuana and that a favorable court decision could be the “motor” that drives the debate about marijuana in Mexico.

“In the medical part, we wouldn’t have any problem implementing it,” Mancera said.

The Supreme Court case involved a petition from a civic organization called the Mexican Society for Responsible and Tolerant Personal Use, which argued that by prohibiting its members from using marijuana, the state was denying their constitutional right to self-determination. The court agreed.

The decision could generate momentum for legislative changes, said Zara Snapp, a policy expert in Mexico City.

“It’s a step in the right direction,” she said. “This has been about the right of a person to choose what they want to do with their bodies if it doesn’t hurt anyone else.”

Powerful forces remain opposed to such changes, however. The Catholic Church in Mexico came out strongly against legalization. An editorial in an archdiocese publication argues that the Supreme Court debate “confuses the public” about a dangerous product.

“A drug is a drug even if it’s sold as a soft medicinal balm. Bad Mexican copycats emulate the neighbor to put on the table of ‘sane democracy’ a bleak, absurd and counterproductive debate,” the editorial read. “Recreational marijuana is a placebo to ease the pain of the social destruction in which we irremediably wallow.”