In Germany, Italy and Spain, it is known as mobbing. French speakers call it harcelement moral. In the Anglo-Saxon world, it is dubbed workplace bullying.

Workplace psycho-terror, as distinct from violent intimidation or sexual harassment, is hard to detect because it involves subtle techniques such as deliberately ignoring or excluding someone, but the effect can be devastating.

Victims take sick leave to avoid intensely painful, humiliating situations, some develop stress-related illnesses and, in the most extreme cases, it can lead to suicide.

Trade unions, professional bodies and nongovernmental organizations across Europe are struggling to fight the hidden scourge, but it isn't easy. Some groups estimate that millions of workers across Europe are suffering, many in silence.

John Doohan, a spokesman for the International Labor Organization in Geneva, said a rise in work-related stress was a clear symptom of a growing problem. "The fact that so much arbitration goes on is already an indicator of the scale of the problem. Why are there so many lawsuits and ombuds offices set up?" he said.

In France, Germany, Italy and Britain, antibullying campaigns have been launched in recent years, as well as hotlines and victims' help groups.

Victims are often picked on not only by a boss but also by one or more colleagues -- known as horizontal mobbing. It can often take the form of character assassination. And in Britain, it is also known as middle-management disease, as this group is a common target.

Mark Pearson, president of the European Human Resources Forum, said that clear-cut cases of the problem had to be dealt with in a tough manner. "Very few employers know how to handle this" when the bullying is not obvious, he said. "You can teach managing diversity well, but not how to handle what are fundamentally destructive impulses in the work force."

In France and Italy, the public sector is more affected because there is less power to fire perpetrators. "The perpetrators take advantage of those who are more vulnerable. The aim is to demean them, break them down, destroy their personality," said Francois Cuffini, a lawyer from France's CRDT trade-union association in Paris. "The aim is not to drive them out of the company -- an office bully usually wants to keep his victim there."

"Workplace harassment is often very difficult to prove because it is subtle," Mr. Cuffini said. "Many employers put their staff under a great deal of pressure to perform. They may be really tough, but that does not amount to harassment."