A St. Paul teacher assaulted by a student at Central High this month is taking legal action against the school district for failing to provide a safe workplace, his attorney said Monday.

The teacher, John Ekblad, 55, is a disciplinarian at the school, knows of violence against staff members and has a blunt message to deliver on behalf of his colleagues.

"Enough is enough," attorney Philip Villaume said. "He feels an obligation to speak out."

Ekblad, who still is suffering from headaches and vision problems as result of the Dec. 4 assault, is expected to speak at a news conference Tuesday.

According to a notice of claims sent to the district, Ekblad has had to return to the hospital numerous times and is unable to work. The notice seeks to trigger mediation talks that could include a request for damages of more than $50,000. An actual suit has yet to be filed.

Jerry Skelly, a schools spokesman, said Monday that the district does not comment on litigation.

The cafeteria assault has rekindled concerns about student discipline and safety in the state's second-largest district.

Ekblad was hospitalized with a concussion after he was assaulted while trying to intervene in a fight between two students.

According to court documents, the 16-year-old brother of one of the combatants slammed Ekblad into a table and chair before slamming him to the floor. The student also choked Ekblad into unconsciousness, the charges say.

Last Friday, the 16-year-old pleaded guilty to felony third-degree assault in juvenile court. He acknowledged causing Ekblad's injuries but told his attorney during the proceeding that he did not remember choking Ekblad or slamming him into a table.

Days after the incident, the St. Paul Federation of Teachers pushed to take its contract talks with the district into mediation. President Denise Rodriguez said then that the issue of school safety was important enough for teachers to call a strike.

Villaume said that the district has known of physical violence toward teachers, but has failed to adequately protect them. In addition, the notice states, the district has failed to take appropriate disciplinary action against students who commit assaultive or violent acts.

Ramsey County Attorney John Choi said recently that the Central High case was the 27th to be presented to his office this year under a gross misdemeanor statute aimed at protecting school officials from being assaulted or harmed. He said that the cases have almost doubled in the past year, and also represent a 60 percent increase over the previous five-year average.

About half of the alleged incidents this year occurred in St. Paul, he said.