SAN DIEGO (AP) – A state judge tentatively rejected San Diego County’s challenge of California’s decade-old law permitting marijuana use for medical purposes before hearing oral arguments from the county meant to change his mind.

San Diego County lawyers maintained that the county should not be bound to act to uphold state laws that conflict with federal statutes, while attorneys for the state argued that California is entitled to pass its own drug laws and legislate programs allowing marijuana use for medical purposes.

“California has authorized the exact same conduct that federal law has prohibited,” argued Thomas Bunton, a senior deputy county counsel. “That’s clearly an obstacle to the objective of Congress to prevent drug abuse.”

Superior Court Judge William R. Nevitt Jr. sat poker-faced through the two-hour hearing, asking procedural questions but giving little indication of whether he intends to revise his tentative ruling. He did not indicate when a final ruling would be issued but set a Dec. 1 deadline for additional briefs on issues related to the case.

San Diego County sued California and its health services director in February regarding the state’s decade-old law permitting use of the drug with a physician’s approval.

Two other California counties, San Bernardino and Merced, joined San Diego as plaintiffs. All three counties have refused to comply with a state requirement that counties issue identification cards for medical marijuana users and maintain a registry of people who apply for the cards.

Five California patients and caregivers, represented by the American Civil Liberties Union, Americans for Safe Access and other advocacy groups, joined the case on the side of the state. A sixth patient, Pamela Sakuda, who suffered from rectal cancer, died earlier this month, said William Dolphin, a spokesperson for ASA.

County officials said they have not decided whether they will appeal if Nevitt stands by his initial ruling.

Supporters of the law said they were prepared for a fight.

“It will go as far as the counties want to take it,” said Adam Wolf, an attorney for the ACLU Drug Law Reform Project who argued part of the case.

California’s law allows people suffering from AIDS, cancer, anorexia, chronic pain, arthritis and migraine and “any other illness for which marijuana provides relief” to grow or possess small amounts of marijuana with a doctor’s recommendation.

Since California voters passed the law with 55 percent approval in 1996, 10 other states have adopted measures protecting qualified patients from prosecution. They are: Alaska, Colorado, Hawaii, Maine, Montana, Nevada, Oregon, Rhode Island, Vermont and Washington.

On Nov. 7, voters in South Dakota rejected a ballot measure to permit marijuana use for medical purposes.

In 2003, the California Legislature amended the 1996 bill to direct county health departments to issue identification cards to medical marijuana users.

Counties, which did not receive money to fulfill the requirement, have been slow to issue ID cards, but San Diego was the first to refuse on legal grounds.