HARRISBURG - A bill fast-tracking through the General Assembly aims to send a tough message to local governments in Pennsylvania: Pass gun-control measures at your own financial peril.

The legislation would penalize municipalities - including Philadelphia and 29 others - that have enacted laws to curb illegal gun sales by requiring them to pay damages and penalties to plaintiffs who challenge those laws in the courts.

The bill is being applauded by the National Rifle Association and condemned by such local officials as Lancaster's mayor and Philadelphia's district attorney.

The proposal, which would expand the rights of the NRA and other interest groups to sue municipalities, easily passed the Republican-controlled House Judiciary Committee last week within days of its introduction and without hearings. It could go to a full House vote as soon as March; its fate in the Senate is unclear.

Under the bill, plaintiffs who challenge local gun-control ordinances could seek reimbursement for double their actual damages, attorney fees and costs, even if the municipality repealed the ordinance before a ruling is made in the case.

A court also might impose a $5,000 penalty and the plaintiff could seek triple damages, in addition to costs and attorney fees, if a judge found the municipality violated the state preemption law.

Boroughs, townships, and cities across the state, including at least nine in  Southeastern Pennsylvania, began enacting local ordinances aimed at cracking down on illegal gun trafficking in 2008 after the General Assembly did not act on a statewide measure to crack down on so-called straw purchases of guns.

The ordinances in Pittsburgh and Philadelphia have stood up to legal challenge. Six cases heard by state courts, including one that went to the state Supreme Court, found that plaintiffs - including individuals and the NRA - did not have standing to sue.

The bill addresses that issue by granting such standing to any "aggrieved party" belonging to a gun rights group - or as the bill puts it, to any "membership organization . . . that is dedicated in whole or in part to protecting the legal, civil, or constitutional rights of its membership."

Supporters of the measure say the local ordinances violate existing state preemption law, which bars localities from enacting their own firearms laws.

"I don't care what the court thinks, the court overstepped its bounds," said Rep. Daryl Metcalfe (R., Butler), the bill's lead sponsor. "Municipalities should not be allowed to represent the people by violating the law."

On the other hand, said Philadelphia District Attorney Seth Williams, local governments should not be penalized for trying to find ways to control gun violence.

"Subjecting them to heavy monetary damages when resources are already scarce is unnecessary," Williams said.

John Hohenwarter, the NRA's Pennsylvania lobbyist, said the debate is not whether the laws have any effect on crime, but whether the ordinances in question are contrary to state law.

"I hope that municipalities recognize they will be held accountable," said Hohenwarter. "Maybe they end up removing the ordinances on their own."

Max Nacheman, director of the gun-control advocacy group CeasefirePA, contended that the bill supporters are wrong about laws already on the books.

"State law preempts local regulation of lawful use, ownership, possession, transfer, or transportation of firearms," Nacheman said. "When a gun is lost or stolen, the lawful owner no longer possesses it, and the person who does does not possess it lawfully."

The local ordinances in question, which have been supported by state groups representing district attorneys and chiefs of police, address straw purchasing of guns by making it mandatory to report lost and stolen firearms.

A straw purchaser is someone with a clean record who buys guns for felons forbidden from owning them. When the guns are retrieved by police after a crime, the straw purchaser claims the weapon was lost or stolen, so police are unable to file charges against the purchaser.

Under Philadelphia's ordinance, enacted in 2008, a person who does not report a lost or stolen firearm within 24 hours faces fines of up to $2,000 and 90 days in jail.

Philadelphia police recover thousands of firearms each year, many of which turn out to be lost or stolen. In 2010, the last year for which police had data available, they recovered more than 4,000 guns, but only 64 were reported lost or stolen.

Lt. Ray Evers of the Philadelphia Police Department's Public Affairs Unit said no one had yet been prosecuted for failing to report a gun lost or stolen. But he added that that was not the sole purpose of the law.

"Having it as an offense is more to make people aware of the issues surrounding stolen firearms," Evers said. "We just want people to report it in a timely fashion. It can save people a lot of aggravation."

A lost or stolen gun could turn up at the scene of an armed robbery or a shooting, he said. "If you lose your gun, it should give you peace of mind to report it."

Leaders of communities with similar mandatory-reporting ordinances say the Metcalfe bill, if enacted, could all but bankrupt them if they were forced to defend themselves in court, or could frighten communities into scrapping laws altogether.

"It's really disheartening," said Lancaster Mayor Rick Gray, who said he has attended more funerals of gun-violence victims then he cares to remember. "It will encourage frivolous lawsuits against communities, and taxpayers will pick up the burden."

Rep. Todd Stephens (R., Montgomery) voted for the bill in the Judiciary Committee and represents the Borough of Ambler - which passed a resolution supporting a state mandatory reporting law.

Stephens, a former federal prosecutor, said he believed that enacting mandatory reporting was both illegal and a waste of police resources in cases where straw buyers file bogus reports. "Just because the municipalities were not successful in changing the law [at the state level] doesn't mean they should violate it," he said.

Gray, the Lancaster mayor who was a criminal defense lawyer for many years, said the only reason anyone would object to the law is to "give lawbreakers an excuse to break it."

He also warned of the bill's costs for cities such as his.

"We have a responsibility to safety to residents and responsibility for fiscal soundness," he said. "As long as we're holding municipalities accountable, I would add that gun owners should be held accountable for their responsibility when they possess a deadly weapon."

Contact staff writer Amy Worden at 717-783-2584 or aworden@phillynews.com, or follow @inkyamy on Twitter.

Inquirer staff writer Allison Steele contributed to this article.