Leaving was made easier by the offer of a job in his uncle’s business. “It was a dead-end job, but it involved driving round the country delivering things and it appealed at the time.”

The decision to return to education at the age of 18 - he is now doing GCSEs in English, maths and information technology at Richmond College - was prompted by his girlfriend. “I saw her getting all these qualifications and realised that I would have to do something if I wanted to be a white-collar worker. ”

Trevor was never illiterate, and could read adequately - “I used to like Tom Sharpe and Judy Blume” - but had difficulties with writing. “It was not legible, I couldn’t spell or punctuate and it was generally below scratch for my age.” In this, he is typical of most people with poor basic skills; pure illiteracy is now rare, but around 16 per cent of the population reads and writes at a level inadequate for employment.

At school, he says, it was easy for his difficulties to be overlooked in a class of 30-plus, while at college there are only 10 in his group. “The teaching here is beautiful- you get all the individual attention you want and it helps meeting other people on your own level.” His teacher, Penny Weaver, has been a basic skills organiser for 16 years. She says that she is now getting more pupils who have left school recently, but attributed this to young people’s growing awareness of the demands of the job market rather than poor teaching at school.

She said the reasons why people end up barely literate are legion. “It can be through truancy, or because children are asked to look after younger siblings, medical problems at school, bullying, teenage pregnancy . . .”

Penny Weaver’s pupils include a woman in her 80s brushing up on grammar, Asians improving their English, and a group of employees made redundant from a local brewery.