PHILADELPHIA (CBS) — Philadelphia’s effort to crack down on predatory towing is being challenged in federal court. Property owners and towing companies are asking that a new law protecting car owners be overturned.

Councilwoman Maria Quinones Sanchez sponsored the bill, requiring that police write a ticket before a car can be towed, after years of complaints about unscrupulous tactics by towers.

The law took effect February first and by mid-Febrary, property owners, later joined private tow companies, had filed suit.

Their attorney, Mike Henry, says police take too long to respond, sometimes don’t respond at all, or sometimes refuse to write a ticket, leaving unauthorized cars in private lots.

The law, he says, “deprives them of an essential attribute of their private property rights which is the ability to exclude other people. Essentially, the government has converted their private parking spaces into public parking.”

READ: City Officials: Towing Companies ‘Going Rogue,’ Illegally Removing Cars

Henry has asked for an injunction to stop enforcement of the law.

The city has asked that the lawsuit be dismissed.

Sanchez says she’d be open to finding ways to speed the process but she’s willing to work with the plaintiffs but not to return towing to the discretion of private tow companies.

“I think the notion that someone can conduct commerce in our streets with nor regulations or framework is ridiculous,” says Sanchez.

She says she’s heard the towing company complaints that business has dropped sharply, from, say, 12 tows a day to three.

“My response is that’s nine people I saved a whole lot of money for,” she said.