After years of wrangling, the Los Angeles City Council on Tuesday approved a medical marijuana ordinance that slaps tougher restrictions on pot clinics and will likely shut down hundreds of dispensaries across the city.

The 9-3 vote drew loud protests from clinic supporters, who plan to challenge it in court, but was also blasted by medical marijuana critics who said allowing any clinics flies in the face of federal law.

"To us it looks like the council has a de facto ban on medical marijuana," said Kris Hermes, spokesman for the pro-medical marijuana group Americans for Safe Access.

Under the new law, which is expected to be signed by Mayor Antonio Villaraigosa, clinics will be barred from operating within 1,000 feet of sensitive areas, such as parks, schools, libraries and churches.

While cash can be used to purchase marijuana, all sales must be documented and the dispensaries cannot make a profit; they can only recover operating expenses.

Over a several-year period, when a loophole-ridden moratorium on pot clinics was in place, the number of dispensaries in Los Angeles exploded to an estimated 800 to 1,000.

Officials hope the new ordinance can ultimately limit the number to 70 - although the 137 that were approved before the moratorium will be allowed to continue operating. Many of those, however, will likely be forced to move to new locations to meet the new restrictions.

Before it becomes law, the City Council has to approve a fee ordinance, which could take effect up to 60 days after approval. Villaraigosa has said his concern was that the measure comply with all state laws.

Officials with the Los Angeles Police Department said they are working on a plan to close the shops that were not properly registered, but are hoping for voluntary compliance with the law.

The City Council has been working on the measure for more than three years and has had to deal with multiple versions after City Attorney Carmen Trutanich rejected the original proposals and called for a much tougher measure banning any sales involving marijuana.

Trutanich said he supported the final measure - which was difficult to craft because of the competing arguments.

"With the passage of the ordinance, Los Angeles is taking an important step forward to ensure that seriously ill and deserving patients have reliable access to safe and lawful sources," Trutanich said in a statement.

Don Duncan, California director of Americans for Safe Access, said the measure represents a bittersweet victory - in that regulations were adopted, but have a wide-ranging impact in closing a number of clinics.

"Although historic, the passage of medical marijuana dispensary regulations by the second-largest city in the country has been undermined by restrictions that threaten to wipe out nearly all of the dispensaries in Los Angeles," Duncan said.

Councilman Bill Rosendahl, a supporter of medical marijuana, voted against the measure because he believes it is too stringent. Council members Bernard Parks and Jan Perry also voted against it.

"This is just crazy," Rosendahl said. "The voters approved medical marijuana and we should make sure it is available to people who need it."

Clinic operators complained there are not suitable locations available - and that landlords are increasing rents because they know the operators have nowhere else to go.

David Backes, who operates a registered collective in Eagle Rock, said he will be forced to move.

"The closest location is nine miles away in an industrial area," Backes said. "And the space available is 23,000 square feet. I only have 1,200 square feet now. It's like moving a store front into an airplane hanger."

But Councilman Parks, a former Los Angeles police chief, said the measure goes too far in allowing marijuana distribution.

"The last time I looked, it is still a violation of federal law," Parks said. "As long as the federal government pre-empts states and municipalities, as long as it is listed as a Schedule One drug, I think it will be impossible to tell if it is being sold. As long as we have federal laws, I don't think this will withstand challenges."

Barbara Monahan Burke of the Studio City Neighborhood Council questioned if the city will be able to enforce the ordinance.

"You will need to give more money to Building and Safety to hire the inspectors to enforce this," Burke said. "Every time we ask Building and Safety to do anything, they tell us they don't have the people to do the job and can't afford to pay the overtime."