Gun-rights groups are planning a peaceful show of force in Lower Merion on Sunday. But in promoting the event, they seem to have spawned a war of words.

The event invites gun owners from around the state to bring lawfully owned permitted weapons to Bala Cynwyd Park at 1 p.m. to protest a township ordinance that refers to gun-carrying in public parks.

The ordinance does not ban legal guns from parks, but rally organizers say it is vaguely written and should be repealed.

In an interview with a Main Line newspaper Wednesday, Kim Stolfer, a Pittsburgh man who founded Firearms Owners Against Crime, said the rally is about civil rights and would be "a Rosa Parks moment."

Gun-control activists, whose strategy had been to avoid and ignore the rally, called the comparison "offensive" and "appalling."

"He's comparing this issue with Rosa Parks? How disrespectful, not only to her and what she stood for, but to every black [person] out here," said Wynona Harper, a member of CeaseFirePA. "You can't take history and compare it to nonsense."

Parks, by refusing to give up her seat to a white man on a city bus in Montgomery, Ala., in 1955, became a symbol of the civil-rights movement.

Stolfer stood by his statement Thursday. "I don't care if they find it offensive or not. That woman stood up for her rights. That's where the comparison is," he said.

"It's different, because she was facing something significantly more threatening," said Eric Patroni, a leader, along with Stolfer, of Concerned Gun Owners of Pennsylvania. "But again, Rosa Parks was fighting for her civil rights, and we're fighting for human rights, the right of one's self-defense."

Each side accused the other of trumped-up rhetoric and argued that its position on guns is fundamentally about safety.

The seeds of the fracas were sown years ago, when municipalities began passing ordinances to regulate things such as carrying guns in parks or reporting lost and stolen guns to police. The issue returned with a vengeance last year, when a new state law allowed membership organizations such as the National Rifle Association to sue to overturn such local ordinances - and pass the legal costs on to taxpayers.

In recent months, almost every local ordinance has been repealed to avoid costly legal battles. Philadelphia, Pittsburgh and Lancaster did not repeal all of their ordinances, and were sued by the NRA in January.

Lower Merion's commissioners debated what to do with an ordinance that read, "No person, except authorized members of the Police Department, shall carry or discharge firearms of any kind in a park without a special permit, unless exempted."

The township determined that anyone who owns a gun legally and has a permit to carry it is "exempted." So they left it untouched.

Stolfer said the ordinance is vague and illegal under a 40-year-old law that says gun regulations are solely the state's domain.

Shira Goodman, executive director of CeaseFirePA, agreed that the ordinance "is a little bit confusing," but said the rally - which is drawing gun owners from across the state who might never otherwise set foot in a Lower Merion park - is more about provocation than civil rights.

"I don't see it as an issue about some great demonstration on protecting rights and freedoms. I see this as a way to intimidate families, to bully the township and say, 'We're going to teach you a lesson because your town wouldn't rescind the ordinance,' " Goodman said.

Stolfer argued that public spaces are safer when people are allowed to arm and defend themselves.

"Malls, parks, schools, movie theaters," he said, citing locations of mass shootings in recent years. "These are all places where people have been led to believe it's safe because there are no guns allowed."

In Lower Merion, public opinion strongly disagrees with that interpretation, said George Manos, a commissioner whose ward includes the Bala Cynwyd Park.

"It's overwhelming, at least here in my ward," he said. "Children play in parks. What sense does it make to allow guns?"

jparks@philly.com 610-313-8117 @JS_Parks