Reading an item in TES recently about claims made against teachers (“Half of claims made against staff found to be baseless”, 20 April), my heart skipped a beat. Occasionally, you encounter a parent who becomes a serious problem. For me, Mrs Pearson fell into that category. Her son David was a withdrawn child who found it difficult to make friends. Although generally well behaved, even as an infant he could be roused by other children into bouts of intense anger. He’d clench his fists and shake, sometimes lash out violently, and then avoid speaking for long periods.

But his general knowledge was good and his teachers worked hard to keep him interested. His mother seemed well educated and asked for lots of homework because she “wanted him to go to university”, but the homework was never done. One morning, when we asked her why, she merely said she knew a great deal about education because she’d been a lecturer, writer, social worker, teacher and psychologist. We began to worry.

When David reached Year 6, he became very unkempt and we learned that Dad had left home. David bitterly resented this. He began rebelling against his mother, arriving very late at school. When we met with Mum, she defended her son unconditionally. “I’ve examined the statistics,” she said, “and it’s a proven fact that children who are late for school always do better in life.”

Things didn’t improve and we met with her repeatedly as David’s behaviour rapidly deteriorated. I was concerned that David told us he was allowed to do whatever he liked, and his tiredness indicated that he’d been on his computer half the night. I felt Mum might need help, too - a view that was reinforced when she withdrew him from school lunches on the grounds that he was being bullied in the playground and, to his utter embarrassment, sat with him on a tiny patch of grass opposite the school, feeding him kebab and chips.

Then the school began receiving bizarre daily emails, always preceded by a telephone call telling us to check our inbox. The letters were threatening, accusatory and offensive. Soon after, Mrs Pearson managed to bypass security and strode into assembly, attempting to give every member of staff a letter stating that she’d spoken with people at a very high level and had arranged with the governors to have me removed from the school immediately. I led her gently, but very firmly, to the school gate.

The emails resumed and I passed the matter to the local beat officer, who visited Mrs Pearson at home to give her an official warning. The next day, an email told me that she didn’t take kindly to a visitation from the police and had employed a barrister to mount a case against my evil regime at the school. I contacted the welfare services who, incredibly, gave her a “telephone assessment” and told me everything was fine. I feared even more for David and pushed for something to be done. She immediately withdrew him from our school and put him in what she described as “a lovely little school with a proper headmaster”. It was a school in special measures, and just what he didn’t need.

We did as much as we could for David, but it is heartbreaking when you see a child’s life being messed up and you can do little about it. Philip Larkin’s ominous line springs to mind: “They fuck you up, your mum and dad...”

Mike Kent is a retired primary school headteacher. Email: mikejkent@aol.com.