Herbert, who represents Vancouver-West End, said a man came into his constituency office on Friday, demanding to see him.
The man started shouting homophobic slurs at his assistant and complaining about the rainbow flags hanging from his office window and at a nearby community centre, Herbert said.
The New Democrat politician said he was in the office but did not witness the incident. He said the suspect punched a hole in the door and his assistant in the face before taking off.
"I heard a loud bang and was up to the front of the office to see what was going on," Herbert said in a phone interview.
"I heard a shout about rainbow flags and as I arrived at the front door, the man was just exiting the office. I phoned the police at that point ... and the police came and arrested him."
Vancouver police spokesman Sgt. Randy Fincham confirmed Monday that officers arrived at Herbert's office and arrested an intoxicated man who was standing on the sidewalk near the MLA's office.
The 53-year-old Vancouver man was released without being charged but police said they will be recommending charges. The suspect is scheduled to appear in court in April, when the unspecified charges are expected to be sworn, said Fincham.
"Due the nature of the allegations, the incident is being investigated by the Vancouver Police Hate Crimes Unit," he said in a written statement.
Herbert, who is openly gay and represents a Vancouver neighbourhood known for its vibrant gay culture, said he put up the rainbow flag to support lesbian, gay, bisexual and trangender people in Russia during the Winter Olympics.
Rainbow flags were raised this month at various city halls and legislatures across Canada as a sign of solidarity after Russia passed anti-gay laws last year that prohibit so-called pro-gay propaganda.
While no stranger to the occasional hateful email, Herbert said the incident on Friday left him and his assistant shocked.
However, the attack has only encouraged him to redouble efforts to stand against hate, he said.
"Too many times have I met people who said I was attacked, or somebody did something horrible to me for who I am, and then decided not to do anything about it, to not press charges," he said.
"Often times people are made to feel it's their fault they were attacked for who they are, when the reality is the person who is doing the violence is the person who has to pay the price."
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