Fairfax County took a tentative step Tuesday toward outlawing loaded shotguns and rifles on roadways, an action prompted by Democratic state lawmakers that taps into the hardened divisions over gun regulation in Virginia.

A motion approved unanimously by the Board of Supervisors directs county staff to study whether Fairfax should take advantage of a 2004 state hunting law that allows local jurisdictions to bar most people from driving with loaded shotguns and rifles.

The Democrat-controlled board will act on the staff’s recommendation in June.

In Northern Virginia, only Loudoun and Fauquier counties and the city of Alexandria have barred driving with loaded shotguns and rifles. The state law allows fines of up to $100.

Fairfax board Chairman Sharon Bulova (D-At Large), who introduced the motion, said a ban might be hard to enforce. But she added that such a law could help persuade the General Assembly that there is support in Virginia’s largest jurisdiction for passing tougher state gun measures.

“Fairfax County has consistently supported efforts by General Assembly members to grant us the authority to prohibit the carrying of firearms on county property, like the government center and rec centers,” Bulova said.

The little-known law regarding shotguns and rifles was meant as a safety measure for hunters. It has become a political magnet in Northern Virginia, as passions around the gun debate build in the months before the November congressional elections.

State Sen. Scott A. Surovell (D-Fairfax) led a group of Democratic state lawmakers in a push to persuade Fairfax and Prince William counties to take advantage of the law after Democrats failed to pass gun legislation in Richmond.

Prince William Board of County Supervisors Chairman Corey A. Stewart (At Large), who is seeking the Republican nomination to challenge U.S. Sen. Tim Kaine (D) in the November election, has ridiculed the effort to ban loaded rifles and shotguns.

Prince William Supervisor Frank J. Principi (D-Woodbridge) said he doesn’t expect the county’s Republican-controlled board to pass any gun reforms. But, he said, he still plans to pursue a ban for loaded shotguns and rifles on roads later this month.

“I think it’s necessary and important to continue this national dialogue we’re having about gun violence,” Principi said. So far, he said, he’s received angry messages that “basically tell me to leave well enough alone.”