I don't see the modern teachers' concern. In my day the secondary school tutor used to tell us our parents HAD to pay a fee at the start of each term, that is was obligatory. I always thought it was a cheek and what sort of law allowed for this demand when we'd all already paid our rates & taxes. The teachers didn't seem to mind then.
(Years & years later I read that such demands were supposed to be voluntary contributions. Like hell they were. Those who hadn't yet paid were asked on a daily basis and asked when the money was going to be paid.)