Alistair Anderson, managing director of a counselling service called in as a witness in both cases, said that workplace stress was on the increase and that unless employers responded, they could face mounting legal action.
'If companies don't put in place some form of occupational support, they will be vulnerable,' he said. 'The only way out for people who are unhappy and stressed is to have some form of legal retribution.'
In one of the cases, a married women in her mid-30s was dismissed by a manufacturing company for 'failing to do her job properly'. She is claiming that stress through overwork contributed directly to a gynaecological disorder which required surgery.
The second involves another women, in her late 30s, who alleges that being forced to work 10-15 hour days by a City firm was the prime cause of a nervous breakdown, which has left her suffering from clinical depression.
These actions follow the suit brought by Chris Johnston, a junior doctor, against Camden and Islington Health Authority over a nervous breakdown, which he says was caused by working excessively long hours. The case will be heard in the High Court next week.
Cary Cooper, a professor in organizational psychology at Manchester School of Management, is about to conduct a national survey of lawyers to see how many such cases have been raised in the past five years: 'We suspect that there have been a lot, but you never hear about them because they are settled out of court. These cases could really set a precedent, and once we have a precedent then things will really take off.
'There is no question that we are going to end up like the United States, Australia and Canada, where stress is a legitimate industrial injury.' In America, one in eight compensation claims are brought because of work-related stress.
According to Professor Cooper, anxiety in the workplace has been fuelled by the recession. In the service sectors, redundancies have left less people doing the same volume of work. Fear of redundancy preys on those who remain.
The social costs of capitalism have figured on the Conservative Party's agenda since the beginning of this year.
Alistair Burt, Under-Secretary of State for Social Security, told a conference of Scottish Tories in June that by forcing employees to spend 'outrageous' hours at work away from their children, businesses were partly to blame for the break- up of the family.
And last January, Virginia Bottomley, the Secretary of State for Health, launched a campaign to reduce workplace depression and anxiety, which led to the loss of 80 million working days annually.
Next year, the Health and Safety Executive will announce guidelines advising employers on how to recognise and prevent stress in the workplace. An HSE spokesman said: 'The causes and forms of stress are highly complex and individual workplaces vary. There is no single blueprint for action.'
But Professor Cooper believes that while such guidelines will not be statutory, 'they will become the basis on which cases can be brought.'