Maggie Hartford looks at how trade unions are taking to the classroom to get across their message Pictures of the Rover Cabriolet and the new Mini adorn the walls of the technology classroom where Year 11 are having a careers talk. But they are not being asked whether they want to work at the car factory, with children or animals, or if they have an aptitude for numbers. Instead, postman Mr Tony Clack is talking about dog bites.

He is legal and medical secretary for the local branch of the Communications Workers' Union, and he convinces them that for his members, being bitten by dogs is not a laughing matter. Some 40 per cent of damages claims for accidents involve dog bites, and the repercussions can be serious.

Mr Clack is there to explain to the students how trade unions work, and the dog bite stories are examples of how union membership can bring practical advantages. His anecdotes seem to go down fairly well, but it's not until his CWU colleague Mr Mark Evans asks a few more questions that the students really come to life. "If there was anything that you could change about school life what would it be? What do you dislike about school? When you start work, what do you expect an employer to provide? What would you consider a health and safety problem?"

Mr Evans gets the usual moans about school life no more homework and more free periods. The teacher cunningly turns this into a constructive discussion about time management and different ways of organising your personal life so that you are not late for school.

Mr Clack, however, is sympathetic to the concerns of Heather, Gemma and Rachel, who are particularly opposed to a new electronic register system which has been introduced at Peers School, Littlemore. Can employees can be trusted to do their job conscientiously without being monitored and would that improve their productivity? Mr Clack says: "We have a system at the Royal Mail where we have to sign in the time we start work. Now we will have electronic swipe cards and I can see why you may feel it is an infringement of civil liberties."

The discussion includes hardy school perennials "Things haven't changed much since I was at school," Mr Evans is heard to say at one point during the informal discussion. He points out that most of the students' concerns fit into the traditional categories dealt with by trade unions health and safety, hours, holidays and pay and would be even more relevant when they started work.

"If you have a problem with a manager or colleague, you can discuss it with your trade union," he says. "Research shows that 86 per cent of bullying at work is by people's immediate line manager. If you come across problems, the union is there to help."

Mr Clack describes the background to the most recent postal strike in Oxfordshire, when 100 postal workers in Abingdon walked out in support of a colleague who faced the sack for allegedly failing to deliver mail.

Mr Evans sums up: "When you start work, you will come across things that are not fair.

"It may be because you are a woman, your sexual preference or race. A trade union could help you and you can tackle these things more effectively as a group."

It is the second year that Peers has invited the Oxford Trades Union Council to send representatives into the classroom. According to Peers teacher Mr Ian Jones, the students find it easy to grasp the possible advantages of trade union membership as a glorified insurance scheme, giving individuals protection against the vagaries of working life. The idea of acting collectively, rather than individually, is more difficult to get over.

The school is a stone's throw from the Rover factory, and the students come from a catchment area which would once have included large numbers of car workers. Now it includes the Oxford Science Park as well as the business and retail park built on the former North and South Works. Times have changed, although Peers has strong links with the company and Mr Jones is keen to encourage his more practically-minded pupils to consider careers in engineering.

Mr Jones said: "The students have a keen sense of injustice both for themselves and on behalf of other people all they need is a label for it. The concept of acting together is more difficult to get across.

"We have a school council, and that helps them to understand how to raise issues constructively, but it would be a brave school that allowed decisions to be made by a student body."

From September, all schools in Britain will have to teach citizenship, which will become part of the National Curriculum. The Government believes that Thatcherism has left a legacy of selfishness, with young people reluctant to get involved in civic life and voluntary activities, leading to a dwindling supply of everything from Scout leaders to local councillors. Some 6-7m has been allocated to the project, although teachers are still not clear exactly what the syllabus will be.

Mr Jones said: "It is not the old-style British constitution as well as understanding the system, students will have to know how it works and how you can use the institutions in real life. It links in with our careers work it's part of preparing them for life after school."