A "dangerous" teacher who tried to strangle his boss after threatening to kill him has been banned from the profession indefinitely.
Arek Bielecki also attacked a colleague with scissors and headbutted him. He was imprisoned after the attacks on staff at Monteagle Primary School in Dagenham, Essex, last year.
Mr Bielecki, now released from Pentonville prison, still "presents a danger to fellow teachers and may be a danger to pupils", according to a General Teaching Council for England (GTC) panel.
He was convicted of affray, two counts of assault occasioning actual bodily harm and threats to kill in June 2010 at Snaresbrook Crown Court, and was given an "indefinite sentence" because he was a danger to the public.
Mr Bielecki, an overseas-trained teacher believed to be Polish, tried to attack another teacher with a pair of scissors during a staff meeting on the first day of term in January 2010. His colleague defended himself by holding up a fire extinguisher. After they left the meeting, a second confrontation took place. The teacher said Mr Bielecki headbutted him.
During a disciplinary hearing in March 2010, Mr Bielecki said he was attacked first and was acting in self-defence. He alleged he had been subjected to attacks by the other teacher on earlier occasions and had been under severe stress at the time.
Mr Bielecki was dismissed from his job after the disciplinary hearing. The next day he returned to the school and told then headteacher Nicholas Munns he was going to kill him. He punched Mr Munns "hard to the face", knocked him to the ground and throttled him.
Mr Munns had to be rescued by other members of staff. He sustained injuries to his neck, eye, shoulder and leg, and was taken to hospital.
The GTC panel said the "unprovoked violent attacks" constituted behaviour that is "inconsistent" with the conduct expected of a teacher.
It noted that Mr Bielecki was experiencing personal difficulties and was suffering from stress. It also heard "suggestions" that he may have been provoked.
The panel said: "However, Mr Bielecki's behaviour was wholly out of proportion to any provocation there might have been. His conduct was premeditated, and all the incidents involved violent disorder on school premises.
"Furthermore, Mr Bielecki presents a danger to fellow teachers and may be a danger to pupils."
It added that he had "a serious attitudinal problem which undermines the trust and confidence which teachers must have in their colleagues".
"To maintain confidence in the profession, and to declare and uphold proper standards of conduct, nothing less than an indefinite prohibition order is appropriate and proportionate," the panel said.