Joey Gibson has been charged with rioting in connection to a May Day fight at a Northeast Portland cidery, according to his attorney.

Gibson, the leader of the right-wing group Patriot Prayer, told talk radio host Lars Larson on Thursday that he was preparing to turn himself in to authorities. Gibson contended the charge is intended to prevent him from joining a high-profile protest scheduled for Saturday on Portland’s downtown waterfront. As of Thursday night, jail booking records did not show that he’d been processed.

“I think it’s a shame," Gibson said on the radio program. "This is a complete attack on the First Amendment. I literally stood on a sidewalk and got attacked.”

The charge comes as police continue to arrest right-wing demonstrators accused of clashing with left-wing adversaries May 1 outside Cider Riot. It also comes to light two days before the dueling demonstrations, which have attracted national attention and are expected to draw hundreds to downtown.

The city’s mayor and police chief have promised a larger turnout by police Saturday and vowed to use the full force of the law against those who commit acts of violence and vandalism.

The charge against Gibson stems from a May Day clash that ensued when about 20 right-wing protesters, including Gibson, arrived at Cider Riot, which was hosting a celebration that drew people who participated in demonstrations earlier in the day.

Video shows people using chemical spray and several people fighting.

Gibson’s lawyer, James Buchal, said none of the multiple videos from the Cider Riot altercation shows Gibson being violent.

“If Mr. Gibson’s conduct on May 1st constitutes ‘riot,’ so does the conduct of thousands of peaceful demonstrators who have appeared on the streets of Portland standing near violent Antifa members,” Buchal said in a statement. “The District Attorney’s decision to destroy constitutional protections against free speech by charging a peaceful protester with a crime of violence makes this a dark day for the rule of law in Oregon.”

Abram Goldman-Armstrong, Cider Riot’s owner, filed a $1 million lawsuit against Gibson and other right-wing protesters just two days after the incident.

Gibson argued in court filings that the case be moved out of Multnomah County, because the city and surrounding area is “so hostile and prejudicial that anyone who dares treat me as anything other than a violent racist Nazi will suffer adverse consequences.”

Buchal, the attorney, wrote that Gibson “cannot appear in public” without encountering masked Antifa members “who spit upon him and physically attack him.”

Buchal said the criminal proceedings against Gibson “are part and parcel of the dishonest campaign by Portland leaders to blame out-of-town demonstrators for violence that began and persists because Antifa wants to shut down any right-wing demonstrations in Portland.”

Gibson didn’t respond to multiple phone calls and text messages seeking comment Thursday.

-- Jim Ryan, Andrew Theen and Shane Dixon Kavanaugh

Elliot Njus and Maxine Bernstein of The Oregonian/OregonLive staff contributed to this report