Robert Cox, 59, told a tribunal that he tried to take his own life twice after becoming 'unemployable' following his dismissal.
In what has become an all-too-common occurrence in schools up and down the land, Mr Cox had to deal with an unruly teenager who refused to accept his authority.
He had told the boy to sit down in an effort to prevent the teen 'acting up' with other boys in front of a teacher.
Instead of obeying, the boy launched into a tirade and threw his banana milkshake over him.
Mr Cox said he believed the boy was about to throw a chair at him and so held his arms and pinned him to a chair.
The incident was captured on CCTV and an investigation was launched into the incident – even though neither the boy nor his parents complained.
The investigating panel deemed his actions inappropriate. They watched the footage and did not believe the boy was about to throw a chair.
They believed Mr Cox's actions and words escalated, rather than calmed, the situation.
Mr Cox, who was a teacher for 13 years, said at the tribunal: "It has had a huge impact on me. I can't get another job now and our financial situation is dire, to say the least.
"In all other public buildings you see posters saying abusive language and behaviour will not be tolerated.
"That is not the case at Bemrose. Instead, if you act within the school guidelines to protect yourself, to protect other students and to prevent an escalation of the situation, you are penalised.
"Senior management at Bemrose don't support staff in general at all.
"Just before this incident, a meeting to discuss pupil behaviour and workload was called by the unions and we didn't get past the topic of pupil behaviour because it is considered by the staff to be so bad.
"I worry for my colleagues still there because the message this sends out is that if pupils threaten their teacher, the teacher is likely to be dismissed."
Mr Cox said the pupil involved in abusing him was excluded for four days. Governors ruled that he had used excessive force and had escalated rather than calmed the situation.
Jo Ward, head teacher at the school, rejected Mr Cox's allegations about poor pupil behaviour and a lack of involvement from senior managers.
She said: "The senior staff are very experienced and get involved with the children and we have got a very secure understanding of the school.
"I would point you to the increase in our examination results. Children don't perform like that if they are misbehaving – they can't."
She said a system was also in place to support staff who may be having problems in a classroom.
The judge's decision is due in two weeks.
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