Virginia house Democrats passed a bill on Tuesday banning the sale of "assault weapons" and calling for the confiscation of magazines capable of holding more than 12 rounds.

The bill would outlaw new sales of some of the country's most popular firearms, including the AR-15. It would also make possession of ammunition magazines capable of holding more than 12 rounds punishable by up to one year in prison even if the magazines were legally purchased.

The bill, known as HB961, passed the House of Delegates by a vote of 51 to 48 with all Republicans and several Democrats voicing opposition. It is the most controversial measure Democratic lawmakers and Governor Ralph Northam (D.) have advanced since taking control of both houses of the state legislature in November. If signed into law, it would be among the strictest bans in the country.

The National Shooting Sports Foundation, the gun industry's trade group, estimates that the legislation could affect hundreds of thousands or even millions of Virginians, especially since the vast majority of modern firearms come standard with magazines that hold more than 12 rounds.

"This bill would affect more than just your modern sporting rifles like the AR-15," Mark Oliva, a spokesman for the group, told the Washington Free Beacon last week. "It would affect the vast majority of handguns."

Tuesday's vote is the latest development in Virginia's gun-control debate. Democrats' push for new restrictions has prompted the vast majority of the state's counties to pass "Second Amendment sanctuary" resolutions. Tens of thousands of people rallied against gun control at the state capital last month, and gun purchases surged throughout the state. The grassroots backlash has led state senate Democrats to moderate their proposals—including the assault weapons ban—but has not convinced lawmakers to drop such measures altogether.

The National Rifle Association, which lobbied against the house bill and other gun-control legislation, criticized Democrats for passing the bill and accused them of being bought by billionaire gun-control activist Michael Bloomberg.

"HB961 will turn law-abiding Virginians into criminals overnight," Catherine Mortensen, an NRA spokeswoman, told the Free Beacon. "Under this bill, anyone who owns a standard capacity magazine must submit to mandatory confiscation or face one year in jail for each magazine they own. No law-abiding Virginian will be able to buy an AR-15—America's most popular all-purpose sporting rifle. After receiving money from Michael Bloomberg, House leaders have their hands out for more and clearly have no regard for the will of their constituents."

Everytown for Gun Safety, which is backed by Bloomberg and spent $2.5 million on the 2019 election, did not immediately respond to a request for comment. March for Our Lives, which recently proposed confiscating up to 117 million firearms, tweeted that it was "so happy" about the passage of HB961. The Brady Campaign, another prominent gun-control group, cheered the vote as "a heartening embrace of common-sense policies."

"This is a sensible action," Kris Brown, the group's president, said in a statement. "We applaud the Delegates for passing this bill and look to the Virginia Senate to ensure that this bill becomes law."

Virginians would be able until January 2021 to turn in their offending magazines without facing jail time for possessing them. The Brady Campaign said the confiscation scheme was "reasonable," pointing to similar restrictions in New Jersey, D.C., and Hawaii—though those laws have seen little or no compliance.

"Other states have implemented analogous laws with analogous pathways and timeframes for compliance," Liam Sullivan, a Brady Campaign spokesman, told the Free Beacon. "The timeframe included in this bill is a reasonable period to allow individuals in Virginia to comply with the law. We appreciate and support those compliance periods, after which stated and reasonable enforcement under the law will be left up to the appropriate authorities."

The bill now awaits a vote in the state senate where it may face stiff opposition. The senate has passed five gun-control bills—including universal background checks, a red flag bill, and a one-gun-per-month purchase restriction. However, the Democrat-controlled chamber has balked at other major gun-control legislation. On Tuesday, it voted down a bill that would have made it a crime not to report a lost or stolen gun within 24 hours.

State senator Lynwood Lewis (D.) has already publicly said he would not vote for a new ban. Three other Democratic senators criticized previous iterations of the "assault weapons" ban, according to the Associated Press. If one of those three Democrats join Republicans to vote against HB961, the ban and confiscation plan will not pass.