WASHINGTON – The Supreme Court has agreed to consider whether worshippers of a Brazilian-based Christian faith can use hallucinogenic tea during their services, in a case that could shape the federal government’s obligations toward religious practitioners.

The Bush administration, which has frequently sided with religious practitioners seeking special accommodations under the law, is in this case asking the court to ban the substance over the objections of the church and lower courts.

The tea, called hoasca, is made of two Amazonian rain forest plants and contains a substance that is banned under federal drug laws. Church members say the tea connects them to God.

“This is their religious sacrament. If the tea is forbidden, it would be the same as telling a Catholic they could not receive communion,” said the church’s lawyer, Nancy Hollander.

Members of the church, the O Centro Espirita Beneficiente Uniao do Vegetal, which has roughly 140 adherents in America, claim the right to use the tea under a federal law called the Religious Freedom Restoration Act. The law requires the government to accommodate religious practices unless it can show a compelling interest in not doing so.

So far, lower courts have sided with the church and issued injunctions preventing the government from interfering with use of the tea.

After a two-week trial, the district court found that the tea was not sufficiently dangerous to justify banning it from the church’s services.

However, the government wants courts to consider any substance dangerous if one of its ingredients is listed as a federally banned substance.

In the U.S. Court of Appeals for the 10th Circuit, Judge Michael McConnell, who is frequently mentioned as a possible candidate for the Supreme Court and a strong supporter of religious liberties, found that the government did not have a compelling reason to deprive the church of its tea, despite the fact that it contains small amounts of dimethyltryptamine, or DMT. The RFRA does not include an exception for drug laws, he wrote.

“Congress’ general conclusion that DMT is dangerous in the abstract does not establish that the government has a compelling interest in prohibiting the consumption of hoasca under the conditions presented in this case,” wrote Judge McConnell.

The Bush administration asked the Supreme Court to review the lower court decisions, arguing that the tea violates drug laws and its importation from Brazil violates international treaties.

Allowing the decisions to stand would result in “enjoining enforcement of the nation’s drug-control laws, compelling violation of an international treaty, imperiling international cooperation in policing transnational drug trafficking, and forcing the government into a joint venture with a religious establishment to assist its importation and distribution of dangerous narcotics into the United States,” the acting solicitor general, Paul Clement, wrote in the brief to the court.

Ms. Hollander said she is surprised the Bush administration is siding against the church, given the administration’s alignment with religious groups, most recently in the case of Ohio prisoners who want to keep items relating to the practice of religions such as Santeria and Satanism in their cells. That case is pending before the Supreme Court.

The case has also drawn a friend-of-the-court brief from several national Christian groups.

“The government’s arguments on appeal, if accepted, would seriously undercut RFRA’s purpose of protecting the religious conscience of all faiths,” states the brief filed with the 10th Circuit by the Center for Law and Religious Freedom for the Christian Legal Society, the National Association of Evangelicals, the General Assembly of the Presbyterian Church, and the Queens Federation of Churches in New York.

The RFRA was passed by Congress in 1993 after the Supreme Court ruled that the states could ban the religious use of peyote by Native Americans. The Supreme Court struck down part of RFRA that applied to state laws, but left it intact with respect to federal laws.

Native Americans continue to use peyote under a special federal statute that protects their religion.

Yesterday’s decision by the Supreme Court to take the tea case, rather than to allow the lower-court decisions to stand, raised concern among some advocates of religious liberties.

“The cynical view would be that they took the case to scale down the reach of RFRA at the federal level, which would be terrible,” the director of the Institute for Public Affairs of the Union of Orthodox Jewish Congregations of America, Nathan Diament, said.