The Boston Free Speech Coalition evolved quietly online and out of the view of authorities in recent months, shaped in part by outrage over violent protests at political rallies and riots on a California campus, a spokesman for the group said Tuesday.

John Medlar, the 23-year-old spokesman, said he and other young men began communicating on the Internet to express alarm over what they viewed as support for protesters who set fires, damaged property, and started fights following the University of California Berkeley’s decision to invite controversial conservative figures to speak.

“We were alarmed that people were OK with fringe anarchists burning down a campus and driving [out] speakers,’’ Medlar said.

As the coalition — which also goes by the name The New Free Speech Movement — prepares to hold a controversial rally on Boston Common on Saturday, a picture of the sponsoring organization has emerged. The group, which until recently planned to include speakers with white nationalist ties at Saturday’s event, has become a source of outrage in Boston, a bane for City Hall, and an outlet for those who feel their voices are being shut out.

“We are not professional activists,’’ Medlar said. “We are just a bunch of volunteers who set out to go do something.’’

Medlar said he has been in contact with police and the city and is working to ensure a permit for Saturday’s event. The city had said the group did not apply for one. But records show an organizer started the process by filling out an online application on the city’s special events portal in July. He did not apply for a permit with the Boston Parks and Recreation Department, which issues permits for large-scale events in the city’s parks.

Medlar said the organizer was “confused by the process,’’ but the group is working with parks and police officials to address the matter. City officials had said that if a permit is issued there would be conditions.

Many Boston-area activists said the group is giving a platform to those who spew racial hate and incite violence.

Iván Espinoza-Madrigal, executive director for the Lawyers’ Committee for Civil Rights and Economic Justice, said the coalition is naive to think that the issue is about the right to free speech if the expression at their rally dissolves into bigotry and violence.

“You have the right to speak. You don’t have the right to threaten or intimidate people,’’ he said. “You don’t have a right to promote racial violence.’’

The group describes itself on Facebook as “a coalition of libertarians, progressives, conservatives, and independents’’ that is willing to “peaceably engage in open dialogue about the threats to, and importance of, free speech and civil liberties.’’

They are mostly young white men in their 20s from places like Newton, Cambridge, and Charlestown who like to think of themselves as “free speech absolutionists,’’ members of the group said.

But civil rights specialists say the group is “alt-lite,’’ and that Saturday’s event is part of a broader effort among some right-wing groups to bring their ideological battles into the streets.

Medlar acknowledged that at least one white nationalist group has been trying to use the rally to insert itself. But he distanced the coalition from that group or any group that espouses violence.

“We denounce the politics of supremacy and violence. We denounce the actions, activities, and tactics of the so-called Antifa (militant leftists) movement. We denounce the normalization of political violence,’’ the group’s Facebook posting said.

One of the Virginia rally’s speakers and another “alt-right’’ member who attended it were also invited to speak at the Boston event months ago. Both are no longer speaking.

The group came on scene in May with a small rally on the Common that drew protests. Police Commissioner William Evans had said the free speech group that held the event was not affiliated with Saturday’s rally. But Medlar said he helped to organize the May rally. Police officials said they are trying to determine who was involved in both rallies.

Coalition members did not anticipate the uproar they would cause when they began planning Saturday’s event at the Parkman Bandstand in May, Medlar and others said.

Just last week, a rally led by neo-Nazis, white supremacists, and white racists led to bloodshed in Charlottesville, Va. Immediately after, there was worry on social media that the speakers who police said incite violent and hate would also speak on the Common.

Amid the uproar, Medlar said the Boston rally organizers were unsure how to respond and panicked. They wavered over whether to continue with their rally or cancel it.

In the confusion, he added, one of the group’s six organizers notified headliner Augustus Invictus, an Orlando activist who took part in the Charlottesville rally, to not to come to Boston. Invictus attracted support from white supremacists when he ran for the US Senate as a Libertarian in Florida in 2016. He told the Globe this week that organizers said they were worried about statements he has made espousing support for a “second American civil war.’’

Tensions between Invictus and the group soared.

“We do not support him due to his willingness to support violence, as well as his Holocaust denial,’’ said one member who would only identify himself as Louis. “So he has been disinvited, and he has pulled out.’’

Six other participants also dropped out as of Tuesday afternoon, Medlar said, and the group’s list of speakers remains in flux. Part of the speakers’ exodus stemmed from uncertainty over whether the event would be held, and the other part has to do with the disinvitation of Invictus. There was a breach of trust between the coalition and speakers, he added.

“It was a mistake on our part we believe,’’ Medlar said. “It created the impression that we are not fully committed to free speech.’’

As of Tuesday afternoon, only three people are confirmed to speak, he said.

Hoping to get a handle on the situation, Medlar said the group decided it needed a “public face’’ to address reporters’ questions and work with the city and police.

Postponing the rally now is not an option. If organizers postpone or cancel it, they would be seen as caving to pressure, the coalition said. Plus, members added, people are going to come.

“In many ways it has already [become] bigger than us,’’ Medlar added. “And we need to get our act together and take control of the reins to make sure we are on course.’’

Meghan E. Irons can be reached at meghan.irons@globe.com. Follow her on Twitter @meghanirons.