Private school teaching had its perks – well-behaved students and a work-life balance – but the emphasis was on protecting the school's bank account not pupils

As I read a story to my year 1 pupils, I felt a whack on my arm. I knew immediately that it was Sara, a girl in my class with autism. But I couldn't say that because if I did she might leave, and the private school l worked for was worried about losing out on fees. Make sense to you? No, it didn't to me either.

I never thought I'd end up teaching in a private school. I was state school educated and did my teacher training in a state school. It was only when I was offered an interview at a private school that I really entertained the idea.

When I got the job I accepted it, telling myself the experience and regular salary would be worth the change. A few months into the role, I thought I'd made the right choice and regaled state school teacher friends with stories of disciplined children and shorter days.

It wasn't until my first parents' evening that I found out about the unwritten rules for teaching in the private sector. The headteacher pulled me aside to warn me about "difficult" parents. Pen in hand, she pointed at photographs of children's faces hanging on a board in her office, giving snippets of information about each of them. "Mark's parents are anxious," she said, urging me to tell them that their son is an "all-rounder" and "great at everything".

I nodded, wondering if I should be taking notes. She continued to scratch at another little face, pointing at it with her pen: "Ayden's parents expect him to go to a selective state school. It's never going to happen, but go with it. Tell them you think he can do it if he tries," she said.

I stared in silence, worried that speaking would make me compliant. Three more faces were tapped before I was able to leave feeling exhausted and bemused by the experience.

After a year spent dodging minefields, a new school year arrived, and with it came my new class: 13 new faces and 13 new minds. Sara was one of them, and from the outset I was sure she had autism. I also realised that an independent school, which couldn't afford special educational teachers but did have newly varnished floors, was not the right place for her.

I spent weeks writing everything down: her classroom behaviour and incidents she was involved in that I couldn't ignore. After two months, I armed myself with several pages of information and brought it to the head's office.

"No, no. Sara can't leave. The numbers are too low," was the response I was met with. "But what about her future?" I asked. Was that the sound of me imploring her? The head's response was dismissive: "She'll be fine. Just give her a bit of one-on-one time in class and we'll explain to her parents that she's a bit behind the others".

I probably should have argued and made a case for Sara, but I couldn't find the energy. Instead I watched any confidence she had slowly fade as she was met with a wall of teachers saying, "stop that" and "be quiet". I spent half my time trying to decipher her childish scribbles and incoherent speech, watching as she was told off for shouting out in assemblies, met by glares from teachers with fingers firmly pressed against pursed lips.

The tipping point was when Sara almost ran off during a school trip. After that I scrawled a hurried note to her parents asking them to meet with me after school. I pleaded with them to have Sara assessed externally. Although they were reluctant at first, and I had to wipe my pained expression from my face every time the classroom door opened, I persisted, showing them her childish scrawls, torn artwork and unmarked test papers.

"There is plenty of hope, if we act now," I said. They left agreeing that an assessment was in order and I stood by the classroom door, my heart pounding as I waved them off like guests who couldn't wait to leave a dinner party.

Sara was just the tip of the iceberg. In this school the beat of deceit was constant. The emphasis was not on teachers looking out for students, but rather on them protecting the school's bank account – permission slip not included.

The rules at my old school were clear: if you are teaching a really clever child, call them average so they don't leave for a better school. If parents ask to change parts of the curriculum say yes and quickly make changes without questioning it. Should you accept dyslexic children into the school? Of course, just get them to sign on the dotted line. Bums on seats, lest we admit defeat.

The bi-annual open mornings, where prospective parents walked around and senior managers hoped they'd hand over a cheque, involved the same things. "Only show them the books of the brightest children," we were told. "Make sure the naughty children have been bribed." Any conversations with parents were always a pitch.

A few months after my chat with her parents, Sara left and I soon followed suit. I've subsequently questioned my integrity and why I stayed. I feel like being there meant I had corroborated in bending the truth. But I stayed because it was easy and I didn't want to be exhausted all the time.

Now I am going back in the state sector, flopping down on a sofa by 4pm will soon be replaced with marking until 6pm, filing papers and planning on the weekends. You know what though, it's OK, because at least I will be a teacher and no longer a school spokesperson.

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