When I started teaching in the early Eighties, I am pretty sure that, like a lot of young teachers at the time, I looked more like a student heading off to a protest march than a future head.

Nevertheless, I was still surprised at my first parents’ evening when the father of Stephanie, one of my A-level economics pupils, asked me: “Why are you teaching her about Marxism when she is supposed to be learning about the economy?”

Given my appearance, it was a reasonable question. But economics was steeped in traditional right-wing politics, and the exam board was scrupulous in ensuring that it was politically balanced. Students could gain points in those days for “eclectic” answers, but there was no risk of communist indoctrination.

But Stephanie’s dad wasn’t interested in my explanation, instead launching into a lecture on the economics of being brought up in Dagenham during the war.

The second occasion on which I was mistaken for a liberal propagandist came a few years later, when I was head of year at a comfortable school in a leafy part of Essex. Aids was suddenly upon the nation, and schools were expected to be at the forefront of the campaign to warn of its dangers. The local authority had sent in its health team to give teachers instruction on what to do. But none of my year tutors were willing to discuss Aids with their groups, so being naive and enthusiastic I decided to do it all myself in groups of three classes together.

Once we had got through the nitty gritty, a mature Year 9 girl asked about the dangers of oral sex. Some immature boys at the front looked puzzled. So I decided to explain what oral sex was. Teachers hid their laughs, the girls tittered, and the boys looked squeamish.

In my pigeon-hole later that day was a complaint from a parent demanding that I explain why I was promoting free sex to the students, along with my Marxist CND propaganda. Just my luck that Stephanie’s younger brother was in the audience and had told his dad.

My final scrape of this variety occurred during my first headship in East London. The News of the World rang to ask why a convicted IRA terrorist had been invited to the school - were all our teachers so left-wing they were telling our pupils these criminals were freedom fighters?

Baffled as to what the reporter was talking about, I insisted the story must have been false. But when I asked around the staffroom, I discovered to my horror that we had, in fact, hosted a former IRA member who had been jailed and released.

However, it wasn’t a liberal plot - the individual was a born-again Christian and our evangelical (and hardly left-wing) head of RE had invited him to espouse the virtues of converting.

Trevor Averre-Beeson, Former head of three London schools and director of Lilac Sky Schools. (www.lilacskyschools.co.uk).