Portland Mayor Ted Wheeler has asked the federal government to revoke a permit for what he described as an alt-right demonstration planned Sunday at Terry Schrunk Plaza across from City Hall.

Wheeler also said the city will not issue permits for such events, and appealed to the organizers to cancel them. He asked the federal government not to issue a permit for a second event, an anti-Muslim march planned for June 10th.

"Our city is in mourning, our community's anger is real, and the timing and subject of these events can only exacerbate an already difficult situation," Wheeler wrote on Facebook, referring to the stabbing attack on a MAX train Friday that left two men dead and a third wounded. "I urge them to ask their supporters to stay away from Portland."

Police have said the suspect in the stabbings was yelling slurs at two teenage girls on the train, one of whom was wearing a hijab, when the other men intervened to try to talk him down.

The purpose of the June 4th free speech rally in downtown Portland is to "bring back strength and courage to those who believe in freedom," according to the organizer's Facebook page. Vancouver-based Patriot Prayer has held other "free speech rallies," including one in Montavilla last month where the suspect in the Friday MAX train killings – Jeremy Joseph Christian – attended and reportedly yelled racial epithets and "Die Muslims!"

Event organizer Joey Gibson has distanced himself from Christian, and told The Oregonian/OregonLive "we were clearly asking (Christian) to leave" the April event.

But in a video posted to Facebook Sunday, Gibson discussed security for the June 4th rally and said "there's gonna be more intensity, there's gonna be more threats." Gibson anticipated counter protesters from an anti-fascist group called Antifa, who he accused of "using the deaths of these two people – and Jeremy Christian – they're using it to get Portland all rowdy about our June 4th rally."

Wheeler's statement that the city would deny permits to alt-right demonstrators could raise constitutional issues. According to the American Civil Liberties Union of Oregon, governments can require permits for peaceful protests as long as they "treat all groups the same."

"The government cannot impose permit restrictions or deny a permit simply because it does not like the message of a certain speaker or group," according to the ACLU of Oregon's website.

Mat dos Santos, ACLU Oregon's legal director, tweeted on Monday that "Our hearts are broken, but government censorship is not the answer. We must defend the constitution even when it is uncomfortable."

When asked whether Wheeler believes his refusal to grant permits is constitutional, spokesman Michael Cox responded that the mayor "believes it's right." He later wrote on Twitter that Wheeler is also concerned about the potential for violence.

-- Hillary Borrud

503-294-4034; @hborrud