As Gov. Phil Murphy moves to tighten New Jersey's gun laws, state gun rights advocates -- backed by the National Rifle Association -- are mounting a legal challenge in federal court.

A lawsuit filed Monday by the Association of New Jersey Rifle and Pistol Clubs seeks to throw out the Garden State's handgun permitting rules, which require gun owners prove a "justifiable need" to obtain a license to carry.

Those rules have been in place for decades, and while former Gov. Chris Christie, a Republican, moved to loosen the standard, one of the first moves Murphy, a Democrat, made as governor was to claw back those changes.

Now, emboldened by a favorable court ruling in Washington, D.C., gun rights advocates are asking the courts to deem New Jersey's rules unconstitutional.

The previous standard, which state Attorney General Gurbir Grewal is reinstating, required New Jersey residents demonstrate they have already been the victim of an attack or faced "specific threats" in order to obtain a handgun carry permit.

"By the time you would qualify, you'd already be dead," said Scott Bach, the president of the gun association, adding that it is nearly "impossible for the average citizen to qualify" for a permit.

Bach's group filed the suit on behalf of Thomas Rogers, a Monmouth County man who "runs a large ATM business that causes him to frequently service ATM machines in high-crime areas," according to the complaint.

His application for a carry permit was rejected by police in Wall Township, who found he failed to "demonstrate a special danger" to his life.

The suit names Grewal and Col. Patrick Callahan, the acting head of the State Police, which oversees state handgun rules, as defendants.

The NRA on Tuesday threw its support behind the suit, citing the Washington, D.C. decision, which found similar rules enforced in the nation's capital violated the Second Amendment.

A spokesman for Grewal did not immediately respond to a message seeking comment. At a press conference in January, Murphy made clear his intent to strengthen New Jersey's gun laws, already regarded as among the toughest in the nation.

"There are already too many guns in our streets, and simply adding more to the equation will not make us or our communities any safer," he said.

Federal court decisions over the years have been mixed on how tightly state and local governments can regulate handgun permits.

Bach said on Tuesday he hoped the New Jersey case would prompt the U.S. Supreme Court to take up the issue.

S.P. Sullivan may be reached at ssullivan@njadvancemedia.com. Follow him on Twitter. Find NJ.com on Facebook.