All three members of the Board of Selectmen in Byron favor it, and Head Selectman Anne Simmons-Edmunds said she expects residents to approve it at Monday’s town meeting, a New England institution where townspeople vote up or down on municipal proposals.

“We’re hoping that the town will get on board with us but will accept whatever the town wants,” Simmons-Edmunds said Friday.

Communities from Idaho to Georgia have been inspired to “require” or recommend their residents arm themselves ever since a gunman killed 26 youngsters and educators Dec. 14 in a school in Newtown, Conn., and raised fears among gun owners about an impending restriction on Second Amendment rights.

The article up for a vote in Maine asks, “Shall the town of Byron vote to require all households to have firearms and ammunition to protect the citizens?”

Backed by gun rights supporters, the ordinance is intended to pre-emptively block gun-control laws, MaineAttorney General Janet Mills said, adding that it will be “null and void” even if it passes. It is pre-empted by a 2011 state law that bars municipalities from adopting firearm regulations.

“I think the town is going to have to shoot it down,” Mills said Friday.

That’s what happened this week in Sabattus, in southwestern Maine, where the selectmen took the police chief’s advice and voted not to send a similar proposal to voters. David Marsters, a retiree in Sabbatus, had proposed the ordinance, saying it would act as a hedge against crime.

The idea has also caught on in Nelson, a city of just over 1,300 about 50 miles north of downtown Atlanta, where supporters of the gun-ownership proposal say light police patrols leave city residents virtually unprotected for most of the day.

The proposal contains several exemptions for people who object to owning firearms because of personal beliefs, religious reasons or mental disability. In a statement, Mayor Pro Tem Jonathan Bishop said convicted felons would also be exempted.

“I am in no way attempting to face off with the federal government, only doing what an elected official is supposed to do,” Councilman Duane Cronic, who proposed the ordinance, said in an email Friday. The rule passed unanimously on its first reading and awaits a final vote April 1.

In Kennesaw, Ga., city officials worried at the time of its law’s passage in 1982 that population growth in nearby Atlanta might bring crime to the community, which now has about 30,000 people.

“They wanted to send an anti-crime message, also,” Craydon said. And it has worked, he argued, with crime staying low.

Craydon acknowledged Kennesaw’s ordinance is “unenforceable” and said no attempt has ever been made to do so.

Some communities don’t go so far as to call for required gun ownership.

Spring City, Utah, moved forward with an ordinance this year “recommending” the idea of keeping firearms. Other ordinances have been passed in Virgin, Utah, and Cherry Tree, Pa., largely as symbolic gestures.

A southwestern Idaho town of 900 people, Greenleaf, adopted an ordinance in 2006 that encourages residents who don’t object on religious or other reasons to keep a gun in the house and to seek training on using firearms. City officials said they don’t know how many residents own guns.

In Maine, Byron’s Simmons-Edmunds said that probably 90 percent of the households in town already have a gun and that passage would not mean the town would enforce it by checking every household.

“We not going to invade anybody’s privacy,” Byron’s Simmons-Edmunds said. “We just want to send a statement that we’re not going to give up our guns.”