Not that there is anything special about teachers: the problem also affects police officers, bank clerks, shop workers, journalists, or anyone who works with others. Bullying is causing thousands of workers severe trauma, making them lose sleep, fall ill, turn to alcohol and heavy smoking, even vomit just at the thought of work.
Andrea Adams has become an expert on bullying at work, ever since she compiled a BBC radio programme on the subject five years ago. As a journalist she was intrigued by reports that 50 staff at a bank branch in Wiltshire were being intimidated by their boss, leading to an awful atmosphere at work, and a high staff turnover. A vigilante group of staff's relatives laid in wait one evening at a multi-storey car park, but the manager was saved by being called away to a meeting. "Bullying often makes people feel murderous," says Ms Adams.
After the programme was broadcast, she was deluged by letters from workers relieved to learn they were not the only ones suffering. The programme also changed her life, leading her to write a book, Bullying At Work, to present follow-up programmes on radio and television, speak at personnel and union conferences, and advise companies on how to adopt effective policies against the bully.
Bullying may be carried out by an individual manager, often a person who has been subjected to bullying at work, or violence and intimidation in their childhood, who feels insecure. "I try not to use the word victim," says Ms Adams, "because it is often people who are strong and good at their job that it happens to."
The examples collected by Ms Adams and some unions present a clear picture of how bullies operate. They may be superficially charming, but once in post can change the working atmosphere in weeks. Those people recognised as any type of threat to the bully - because they are effective, intelligent, popular, different, young, ambitious or experienced - may be targeted through a campaign to undermine them.
Job responsibilities may be changed without consultation, allocating people tasks to which they are not suited, enabling the manager to criticise or discipline them. There may be a campaign of vindictiveness, by intercepting phone calls, changing desk and office arrangements, making a fuss over small mistakes, overruling decisions, and, above all, by verbal and physical intimidation.
Challenging the bully can be difficult. Often the bully is close to senior management, thereby cutting off routes to complaints, and ensuring that allegations are not taken seriously. Ms Adams says it is important to fight back. "It rarely happens to just one person, so get together and make a collective complaint - the personnel department will find scale difficult to dismiss. Keep evidence, stick to the facts, log it, date it, note your response and keep correspondence."
But bullying can be a conscious decision by management, originated not at junior but at board level. Intimidating someone to leave their job is cheaper than paying out redundancy settlements.
A few employers, though, are beginning to take the problem seriously. Kent Police has established its own policy, and bullies can be dealt with under the constabulary's disciplinary code. The Police Federation is pressing other forces to copy Kent's example, and Ms Adams is to address a fringe meeting at the federation's conference next month.
Littlewoods is another employer to take a lead, with its "Dignity at Work" policy, launched last September, recognising that staff do not perform at their best unless they are in a positive working environment. "It is a natural extension of our equal opportunities policy," says Melanie Theobald, a principal equal opportunities officer. "We are looking after the individual, based on the principles of fairness and equity."
While harassment is different from bullying - harassment is defined by Kent Police as troubling or annoying people, bullying as using coercion and persecution - Littlewoods says that its "Dignity at Work" gives all victimised staff a grievance procedure, not only those who can claim sexual or racial harassment.
But still the majority of employers fail to recognise the severity of the problem, or have effective policies to deal with it. "I have just done a very big survey," explains Ms Adams. "There were only six out of 31 companies in which there was good support and a complaints procedure. How you find out in advance how good a company is on this I don't know, but when interviewed you could ask for a copy of the policy. If it takes sexual and racial harassment seriously then this may give a clue."
An earlier BBC survey of 53 top British companies found none had a policy on bullying at work; yet 78 per cent of employees had witnessed bullying, and 51 per cent had experienced it.
The Manufacturing, Science and Finance Union, which is running a campaign against the workplace bully, says that only legislation will get to grips with the problem. Ms Adams, who is also calling for new laws, believes that employers may begin to change once more are penalised by industrial tribunals for failing to deal with bullying.
The tragedy, says Ms Adams, is when bullying is inflicted on people in their first jobs. "When it happens to young people they think it's normal workplace behaviour, and go on to do it to others." This can create a cycle of abuse that is impossible to break.
'Bullying at Work' by Andrea Adams, is published by Virago, at £7.99.