Tucson and the Arizona Attorney General are going to court in an unprecedented lawsuit to determine whether the city’s gun destruction policy violates state law.

The Tucson City Council voted 7-0 to challenge Attorney General Mark Brnovich’s assertion that the city’s policy may violate SB1487, a 2013 law that forbids Arizona cities from destroying guns seized by police. The law requires cities to sell seized guns to dealers.

Tucson police have destroyed 4,820 guns since the law took effect.

Brnovich conducted an investigation of the city’s policy in response to a request by Rep. Mark Finchem, R-Oro Valley, under a law enacted in 2016 that requires the attorney general to investigate whenever a lawmaker alleges a city or state subdivision is violating a statute or the Constitution.

Brnovich’s finding means he was required to file a case with the Arizona Supreme Court, which in turn is required to make it a top priority.

Brnovich gave the Tucson City Council until Dec. 6 to either get rid of the city policy or schedule a future council meeting to act.

“While I respect the autonomy of local governments, the City of Tucson’s mandatory gun destruction policy is at direct odds with state statute.  Arizonans depend on the Attorney General to uphold and enforce the law,” Brnovich said in a press release. “Our Supreme Court filing isn’t just about the Second Amendment, it’s about the rule of law.”

The penalty for a city violating a state law or the Constitution is the withholding of state shared revenue, which for Tucson is $176 million in fiscal-year 2017.

Just opening a case with the Supreme Court will mean Tucson will be required to post a bond in the amount of state-shared revenue it has received in the last six months.

 Attorneys for the city are expected to ask the justices to declare that requirement illegal or, at the very least, waive it.

At issue is whether the Tucson ordinance mandating the destruction of the guns is a local or statewide matter.

A city ordinance that conflicts with state law will reign supreme if the ordinance relates to matters of purely local concern.

Tucson argues that its policy is a local issue involving municipal property.

Brnovich argues that regulating firearms is a matter of statewide interest for the purposes of preserving Second Amendment rights, preserving public safety, regulating police departments, and making sure cities don’t waste revenue-generating resources.

Howard Fischer of Capitol Media Services contributed to this article