Pupils at Southgate school may not know it, but they have reason to be grateful that Tanya Harris became a teacher there last September. Thanks to her, some have received support for problems that might have remained hidden but for her ability to pick up signals from troubled teenagers.

Surprisingly, Ms Harris has not acquired this important skill after years of pastoral experience with children. She is a newly qualified art teacher, in her final induction term at the school in Enfield, north London, who credits her success to the 10 weeks of training and two years’ work as an unpaid, volunteer ChildLine counsellor.

She is one of 80 or so teachers who find time - usually four hours at the weekend or after school - to volunteer as a telephone counsellor for ChildLine in one of its 11 call centres around Britain. And one of the many thousands of teachers who volunteer for a cause they believe in. Such people are being celebrated in this the Year of the Volunteer, and in particular in the first week of June: Volunteers’ Week.

Schools are a hive of voluntary activity - from the army of 350,000 governors to the legions of mentors and literacy-scheme readers to the thousands of staff and pupils who provide some kind of service in their communities. And they are well placed to illustrate the manifold benefits of a thriving voluntary sector. For volunteering is a two-way street: individuals who volunteer can benefit as much as, if not more than, the beneficiaries.

For example, of 5,398 pupils aged 11 to 15 who took part in a volunteer community project in the Active Citizens in Schools scheme, 79 per cent said they had gained in confidence; 89 per cent had improved teamwork skills; and 73 per cent their communication skills. Schools reaped the rewards with the vast majority saying that behaviour was better, that staffpupil relationships were enhanced and that the school was viewed in a much better light by the community.

“The point of active citizenship is that pupils identify a problem and solve it for themselves. This gives them a great sense of what lies ahead, in what it means to be a citizen in a community,” says Jason Tanner, a spokesman for Community Service Volunteers (CSV).

A survey by Volunteering England shows that 71 per cent of volunteers who offer their professional skills and experience say volunteering makes them feel happier.

CSV has campaigned for “active citizenship” in schools for more than 40 years. It welcomed the introduction of citizenship into the curriculum in 2002, but fears too many schools are opting for the theoretical rather than a hands-on approach. “Teachers tell us that active citizenship as a subject is fantastic, but we need to provide interesting and innovative ways to encourage young volunteers,” says Jason Tanner.

That is one of the aims of Year of the Volunteer, launched in January by the Chancellor of the Exchequer, Gordon Brown, who spoke of his aim to persuade more than a million extra young people to become community volunteers over the next five years by harnessing “the idealism of young people, to make them partners in human progress”. In October there will be a focus on citizenship and awards to 85 schools.

ChildLine, which takes 2,300 calls a day from children in distress, is seeking 500 new volunteers to help on its 24-hour free helpline; hundreds of child callers cannot get through because of a shortage of counsellors.

Peter Atfield, the charity’s director of personnel, says teachers tell him volunteering enriches their personal and professional lives. “It’s a partnership where everybody benefits; the teachers who volunteer to work with us are fantastically committed.”

Tanya Harris, 32, applied to be a ChildLine counsellor after deciding to train as a teacher; she was anxious to discover how to identify and support an unhappy child in a crowded class. She has not been disappointed: “The training is incredible. It fulfilled all my expectations. It is amazing how clear the signals are that teenagers give when calling out for help.”

Working with ChildLine has made her more confident about being an advocate for pupils. “I also know where the boundaries are and how to refer them on to other professionals without becoming too involved.”

Sophie Berryman, 25, is coming to the end of her PGCE. She already feels more confident about her career thanks to her training as a ChildLine volunteer. “My three-year BA did not include anything on child protection, self-harm, bullying - all the things that children regularly ring ChildLine about,” she says. “So I am sure this has better equipped me for the classroom.”

Newcomers undergo a rigorous assessment programme before being accepted on to the training course, at which point they are expected to commit at least a year to ChildLine. Training involves role play and therapy-type sessions to ensure the trainee has the capacity and temperament to deal with children in a confidential, non-judgmental way.

“At no point do I ever feel that I am on my own. There is always someone experienced around to help and advise you and the debriefing sessions at the end of each shift ensure that you don’t take it all with you,” says Sophie Berryman. She has clearly caught the volunteering bug - she is off to Africa this summer to help out in a school in Ghana.

ChildLine (www.childline.org.uk) has 11 counselling centres around the UK: Belfast, Glasgow, Aberdeen, Leeds, London, Nottingham, Manchester, Swansea, Rhyl, Birmingham and Newton Abbot. ChildLine volunteer recruitment hotline: 0870 3362993.For teachers not able to get directly involved, ChildLine offers in-service courses for schools and pupil workshops through its outreach programme ChiPS (ChildLine in Partnership with Schools).

www.yearofthe volunteer.org;www.csv.org.uk; www.do-it.org.uk; www.mediatrust.org; www.communitychannel.org