The school is very likely acting unlawfully in two distinct areas: illegal exclusions and a failure to deliver statutory SEN provision.
It is completely understandable that you do not want to see the school as "evil" and that you care about the safety of other children. However, schools are bound by strict legal frameworks. Wanting to protect everyone does not give a school permission to bypass the law.
"we can't safely accommodate him today" or "it's best he comes home to calm down" are classic examples of informal and unlawful exclusion.
Every time they send him home informally:- It does not show up on official statutory attendance records, hiding the true extent of his breakdown at school.
It denies you your legal right to appeal or submit written representations to the Governing Body. It deprives your son of his legal right to education.
Throwing a chair or pushing a table when completely overwhelmed is a manifestation of his distress/disability, not calculated malice. Expecting a 9-year-old in a state of sensory overload to "learn he can't behave like this" via strict reprimands rather than providing sensory breaks and de-escalation fails to make reasonable adjustments.
There is a vast difference between placing a child in a mainstream classroom and actually including them. What your son is currently experiencing is integration, not inclusion.
Integration (What is happening now): Placing a child with additional needs into a standard mainstream environment and expecting them to adapt, conform, and cope with the exact same demands as neurotypical peers with the threat of strict discipline or being sent home if they cannot.
True Inclusion (What the law requires): Adapting the environment, teaching methods, and sensory conditions so that the child can access education safely and effectively.
Telling a 9-year-old in sensory overload that he "needs to learn he can't behave like this" misplaces the responsibility. Under the Equality Act 2010 and the SEND Code of Practice, inclusion requires the school to adapt to the child’s disability, not demand that the child mask or suppress their disability until they explode. True inclusion would mean:
Recognising his distress signals before a meltdown occurs.
Allowing him to leave a noisy classroom to go to a designated quiet area without it being treated as a disciplinary failure.
Training new staff on his specific profile rather than applying a blanket "strict" behavioral approach.
Year 5 is historically the point where mainstream primary schools drastically escalate academic pressure, pace, and formal classroom management in preparation for Year 6 Key Stage 2 SATs.
Environmental Shift: Year 5 classrooms often become much more rigid, noisy, and focused on formal table-work, past papers, and silent working time. Teachers feel immense pressure from school management to hit specific attainment targets.
Reduced Tolerance for Disruption: Because of the impending pressure of Year 6 SATs, tolerance for anything that interrupts the structured flow of the lesson drops significantly. This explains why his new teacher may be taking a strict "zero tolerance" stance.
Off-Rolling / Exclusion Push: It is a well-recognised pattern in the state education system that SEN pupils facing high levels of anxiety or dysregulation often see an increase in suspensions or informal "off-rolling" during Year 5. Schools often push for a move to a special school before Year 6 so the pupil's scores do not impact their published SATs performance data, or simply because they feel they lack the resources to support them through the SATs preparation period.
The school are pulling a fast one on you and your son. There's a word for them but I'd have to see you next tuesday to tell you it.