Advocates for expanding Maine’s background check requirement for gun purchases will begin gathering signatures around the state this weekend in an effort to put the issue before voters in November 2016.

The organization Maine Moms Demand Action for Gun Sense filed initial paperwork in August for a ballot initiative that would require background checks on anyone purchasing a gun from a private seller or from non-licensed sellers at a gun show. The Maine Secretary of State’s Office accepted the application as complete Wednesday, allowing the group to begin collecting the 61,123 signatures from Maine voters needed to qualify for the ballot.

Supporters say the expansion would close a loophole that allows individuals who are prohibited from owning a gun to avoid the federal background checks required for purchases at licensed gun dealers.

“We can save lives by closing the deadly loophole in Maine law that makes it far too easy for criminals, domestic abusers, and other dangerous people to get their hands on guns without any background check at all,” Judi Richardson, the mother of a Portland woman shot to death in 2010, said in a statement. “We are now one step closer to giving Mainers the chance to vote up or down on this issue next November.”

The shooting death of Darien Richardson, who was killed in her apartment by an intruder, was never solved. Her mother is one of several individual sponsors of the initiative.

Opponents claim the proposal will only affect law-abiding gun owners and do little to keep guns out of the hands of criminals.

The proposal would require individuals selling guns person-to-person – whether at a gun show or through an ad – to have a registered gun dealer run a background check through the federal system before completing the sale. The initiative contains a number of exemptions from the background checks, including for gun transfers between immediate family members, for hunting trips, to address an imminent threat or sales of antique guns.

The proposal would face stiff opposition if it qualifies for the ballot.

On its website, the organization Gun Owners of Maine called the proposal “the most sweeping infringement on gun rights in Maine history” and a first step toward a national gun registry because every transaction will be run through the background check system.

Todd Tolhurst, president of Gun Owners of Maine, said the existing background check system does not work well because some people who are legally entitled to own a gun are wrongly rejected by the federal system.

Tolhurst also said criminals intent on obtaining a gun rarely buy it themselves but instead work with a “straw purchaser” who can pass a background check and passes the gun along.

“Background checks are so easily circumvented that they do not accomplish what they are supposed to do,” said Tolhurst, whose organization is active in policy debates in Augusta. “What they are good at is keeping law-abiding citizens from obtaining and keeping a gun.”

Tolhurst also pointed out the connection between Maine Moms Demand Action for Gun Sense and the national organization Everytown for Gun Safety, which is heavily funded by former New York City Mayor Michael Bloomberg, a leading advocate for stronger gun laws. Everytown for Gun Safety provided all of the $258,000 in initial campaign donations reported by the Maine group since its registration with the state in August.

Elizabeth Allen, a spokeswoman for Maine Moms Demand Action for Gun Sense, said the local organization has been focused on submitting the ballot question application and setting up the campaign rather than broader fundraising at this point.

“We have lots of volunteers in the state who are eager to contribute their energy or financially,” Allen said.

The organization will be gathering signatures in Portland and is opening offices in Ellsworth and Bangor. The petition drive is being kicked off at a time when guns and gun control laws are generating headlines in Maine and nationally.

As of Thursday, Mainers can carry a concealed handgun without first obtaining a permit from police. The Legislature passed the “concealed carry” bill this year, making Maine one of roughly a half-dozen states in the country to allow residents to legally carry a gun without a permit, although police will still offer permits for those who want to carry a concealed gun in states with reciprocal agreements with Maine.

But after a spate of high-profile shootings – including 10 people killed at an Oregon community college this month – advocates for stronger gun control laws are ramping up efforts on the national level. Any effort to pass gun control laws in the current Congress is unlikely to succeed, however, given the political dynamics in Washington.

A state lawmaker from South Berwick, Democratic Rep. Roberta Beavers, has also requested a bill that would require background checks on private gun sales or transfers. Members of the Legislature’s leadership will meet next week to decide which bills will be considered during next year’s short legislative session.