Today, a judge put off a decision on whether to bar Los Angeles from enforcing its new medical marijuana ordinance against four collectives, leaving the scores of dispensaries that have filed suit in limbo more than three weeks after the law became effective.

Los Angeles County Superior Court Judge Anthony J. Mohr said that he believed the city’s ordinance was imperfect, but also said he was not certain the defects violated the rights of collectives forced to shut down by June 7, when the law went into effect.

“It looks to me as if this statute’s got some shortcomings,” he said.

But Mohr appeared to tilt slightly toward the city’s argument, saying the City Council’s efforts to regain control over public safety issue — the explosive increase in the number of dispensaries — may be valid even if flawed.

“The city is very clearly trying to get control of the situation,” he said.

A decision to grant preliminary injunctions could bring a halt to the city’s efforts to close about 400 dispensaries and might force the City Council to revise the law. Although the injunctions would apply to four dispensaries, scores more would probably seek similar orders.

The stores seeking the injunction are Green Horizon Collective in Chatsworth, 420 Caregivers in Hollywood, 420 Collective in Mar Vista and Organic Healing Center in Eagle Rock.

David Welch, who represents 44 dispensaries in two lawsuits, said the impact of the delay was huge. He has advised his clients to keep their dispensaries closed until there is a decision.

“We’re going to fight until it’s done,” he told about 30 dispensary operators in the hall after the hearing.

Several declined to give their names when asked to comment, fearful of retribution from the city and cognizant of Welch’s advice to be careful when talking to the media. “The doors are closed, but the meter is running,” said one operator who is still paying rent and hoping to reopen.

William W. Carter, the chief deputy city attorney, argued that Los Angeles had a rational basis for limiting the number of dispensaries, noting that they have drawn armed robbers and created nuisances in some neighborhoods.

“The ordinance is attempting to restrict or minimize the number of targets,” he said.

After hours of questioning, Mohr concluded the pivotal issue is whether the City Council can restrict the dispensaries to those that registered with the city in 2007. Welch argued that the provision violates the due process and equal protection rights of collectives that did not register because it was based on an expired moratorium.

Under a moratorium on new outlets that became effective Sept. 14, 2007, all existing dispensaries were required to register by Nov. 13, 2007. But a Los Angeles County Superior Court judge said in an earlier decision that the council failed to follow proper procedures when it extended the ban beyond 45 days, making it invalid at the time of the registration deadline.

Mohr appeared to agree. “I will tell you it’s an imperfect basis,” he said to Carter.

“But it’s still a rational basis,” Carter responded. “It’s based on the lay of the land at a certain date.”

The city’s attorneys argued that if the council had made a mistake, it was simply procedural, could have been easily remedied and should not invalidate the ordinance.

Mohr asked both sides to submit additional briefs by July 23, and he will rule after that.

The judge also rejected several other arguments the dispensaries made against the ordinance. He said it did not matter that they may not have known about the requirement to register.

“Ignorance of the law is no excuse. That’s fundamental,” he said. And he said that the city’s decision to give business tax certificates to dispensaries did not confer a vested property right.

“I’m very much on the city’s side on that,” he said.