Traditionally, the requirement for employers to take reasonable care for the employee's health and safety was limited to physical injury, or the risk of physical injury, to an employee at the workplace.

However, the landmark decision of the High Court in Walker v Northumberland County Council (judgment delivered by Colman J on 16 November 1994) has extended the concept of the duty of care to embrace mental injury suffered by an employee.At common law, the employer must exercise care for the employees' safety.

The common law implies the following duties: (a) a duty to take reasonable steps to provide a safe place of work: General Cleaning Contractors Ltd v Christinan [1953] AC 180; (b) a duty to provide a safe place of work: Thomas v Bristol Aerospace Co [1954] 2 All ER 1; (c) a duty to ensure that the employer employs competent fellow employees to undertake the work: Hudson v Ridge Manufacturing Co Ltd [1957] 2 QB 348; (d) a duty to provide safe plant and equipment: British Aircraft Corp Ltd v Austin [1978] IRLR 332, cf Lindsay v Dunlop Ltd [1980] IRLR 93; (e) a duty to protect employees from unnecessary risk of injury: Charlton v Forrest Printing Ink Co Ltd [1980] IRLR 330; Stokes v Guest Keen & Nettleford (Bol ts & Nuts) Ltd [1968] 1 WLR 1776; Hotson v East Berkshire Area Health Authority [1987] AC 750; Wilsher v Essex Area Health Authority [1988] AC 1074.Many of the cases on the duty of care owed by the employers towards the employees were largely concerned with physical injuries which employees had suffered at the workplace.

Before the Walker decision, it was clear that the duty of care did not extend to situations where employees had suffered mental injury, such as stress, at the workplace, as a result of the heavy work-load commitments imposed upon them by their employers: Petch v Customs & Excise Commissioners [1993] ICR 789.John Walker worked for Northumberland County Council as an area social services officer from 1970 until December 1987.

He was responsible, as manager, for four teams of social services field workers, and he was accountable to the assistant director of the council's social services department.

During the 1980s, Mr Walker's volume of work increased substantially, as did that of his team of field workers, owing to the increasing incidences of child abuse cases with which the staff were required to deal.

The council increased the number of field workers to assist Mr Walker during the period 1974 to 1978, but there was no further increase after 1978.In 1986, Mr Walker suffered his first nervous breakdown as a result of mental exhaustion, acute anxiety, headaches, sleeplessness, irritability, inability to cope with any form of stress, and a tendency to weep and become upset.

Having taken some time off work to recuperate, Mr Walker eventually resumed work and informed his immediate superior that he should be relieved of some of the pressures of work.

The council agreed to another principal field worker being seconded to assist Mr Walker temporarily.However, Mr Walker was later told that the principal field worker was required elsewhere to cover for other members of staff.

Further, during Mr Walker's absence as a result of his first nervous breakdown, a substantial volume of paperwork had accumulated.

He was required to clear the backlog as well as resume his normal day to day duties.

After a short period of break for a holiday, he returned to work, but his stress symptoms increased and he informed his superior he could not be expected to continue in the present situation.

He went on sick leave and was diagnosed to be affected by a state of stress-related anxiety.

At this stage, he had suffered a second nervous breakdown and was obliged to retire from his post.In 1988 Mr Walker was dismissed by the council on the grounds of permanent ill-health.

He claimed damages for breach of duty of care by the council in failing to take reasonable steps to avoid exposing him to the health endangering work-load.

He contended that the council ought to have appreciated that the work-load to which he was exposed might endanger his health, in view of the warnings of excessive work-load communicated to his superiors, and in view of the inherently stressful nature of social services work of that kind.According to Colman J, one of the main legal issues was whether Mr Walker's first illness was caused by a breach of the council's duty of care.

An employer has a duty to provide employees with a reasonably safe system of work, and to protect them from risks which are reasonably foreseeable.

Although the law limited this concept mainly to physical injury suffered by the employee, the duty of care could be extended to cover injury to mental health caused by stress at the workplace.Given that the professional work is intrinsic ally demanding and stressful, at what point is the employer's duty to take protective steps engaged? What assumption is the employer entitled to make about the employee's resilience, mental toughness and stability of character, given that people of clinically normal personality may have a widely differing ability to absorb stress attributable to their work? Colman J stated that once a duty of care had been established, the standard of care required for the performance of that duty must be measured against the yardstick of reasonable conduct on the part of the person who owes the duty.

The law does not impose upon such person the duty of an insurer against all injury or damage caused by him or her, however unlikely or unexpected.The practicability of remedial measures should take into account the resources and facilities at the disposal of the person or institution owing a duty of care: British Railways Board v Herrington [1972] AC 877.

Consideration must also be given to the purpose of the activity which has given rise to the risk of injury.

In the words of Denning LJ in Watt v Hertfordshire County Council [1954] 1 WLR 835, the risk must be balanced 'against the end to be achieved': Gillespie v Commonwealth of Australia [1991] ACTR 1.The Walker decision raises a number of practical considerations.

It makes it clear that an employer may be in breach of an implied term in failing to take reasonable care of the employee's health and safety at the workplace, which includes mental injury.

This may be considered to be a fundamental breach of contract which goes to the root of the contract of employment: Western Excavating (EEC) Ltd v Sharp [1978] ICR 221.The employee may be entitled to treat the contract as having been repudiated by the employer because of the employer's unreasonable conduct in taking steps to minimise stress at the workplace, and also by exposing the employee to high levels of stress through a heavy work-load.

The employee could claim constructive dismissal and claim for damages.

Under s.55(2)(c) of the Employment Protection (Consolidation) Act 1978 (EPCA), an employee can terminate the contract of employment 'with or without notice in circumstances such that he is entitled to terminate it without notice by reason of the employer's conduct'.Clearly the employer's conduct must be sufficiently serious to entitle the employee to leave at once.

If the employee continues to accept the heavy work-load demands and stressful situation after making the complaint, the employee may lose the right to treat himself as discharged, and will be regarded as having elected to affirm the contract.

The onus is on the employee, therefore, to notify his or her employer of the heavy work-load demands upon him or her, and to identify what actions the employer proposes to take to ease the work-load.The employer may be required to distribute some of the employee's work to other colleagues.

Could this possibly lead to an employer reducing the employee's pay as a result of the redistribution of the employee's work? Under s.1 of the Wages Act 1986, it is unlawful (subject to exceptions) for an employer to make any deductions from the wages of any worker employed by him or her.

However, one of the exceptions to this general prohibition is where the worker has signified agreement to the deduction in writing in advance.

Solicitors acting for employers may well consider including an express provision in the contract entitling employers to deduct such amount from the employee's wages as to take account of the reduction in the employee's w ork-load, which has had to be distributed elsewhere.If the employee then brings a claim for unfair dismissal, the employer may be able to argue that it was a fair dismissal related to the employee's capability or incapability in performing the work of the kind which the employee was employed by the employer to do (see s.57(2)(a) of the EPCA 1978).

'Capability' is to be accepted by reference to skill, aptitude, health or any other physical or mental quality (see s.57(4)(a) of the EPCA 1978).However, the industrial tribunal must also have regard to s.57(3) of the EPCA 1978 which states: 'The determination of the question whether the dismissal was fair or unfair, having regard to the reasons shown by the employer, shall depend on whether in the circumstances (including the size and administrative resources of the employer's undertaking) the employer acted reasonably or unreasonably in treating it as a sufficient reason for dismissing the employee; and that question shall be determined in accordance with equity and the substantial merits of the case' (Polkey v AE Dayton Services [1988] AC 344).

The employer may need to consider whether the employee could be offered other suitable alternative employment.The Walker decision concerned a local authority, but the same duty of care principle would apply equally to corporate employers.Another wider implication of the Walker decision is whether a company, as a legal person, could claim damages for stress as a result of actions by third parties.

In Firsteel Cold Rolled Products Ltd v Anaco Precision Pressings Ltd [1994] The Times, 21 November Owen J held that there was no head of damages recognised in English company law which enabled a company to claim for inconvenience, stress and difficulties in the course of its business, caused by the actions of another party, by attributing the inconvenience, stress and difficulties experienced by the directors and employees to the company itself.In the light of the Walker decision, some consideration should be given to identifying factors that could lead to stress at the workplace and to provide ways of minimising the stress levels.

Stress can be defined as a non-specific response of the body to any demands made upon it.

Stress related diseases may by physical or emotional.

The physical symptoms can include allergy, loss of hair, high or low blood pressure, migraine, peptic ulcers and skin disease.

The emotional symptoms can include anxiety, abnormal eating habits, panic attacks, phobias, irritability and abnormal depressive illness.A number of studies have been conducted in professional organisations to identify the areas of stress which employees suffer at the workplace.

They included factors intrinsic to the job; a person's role at the workplace; relations with the organisation; the relationship between home and work; too much work; change in work practice; completing deadlines; unclear objectives; senior partner or partner with aggressive communication styles; inadequate rewards; new management style; too many meetings; too many interruptions; inadequate heating, lighting and ventilation; equipment breakdowns; and inability to control your own pace of work because of competing and excessive demands from other partners.Some of the practical ways of minimising stress include developing more variety in your job; getting some feedback from your employers; not taking on more work than you can handle; becoming assertive; only dealing with the problems you own and not inheriting other people's problems; learning to say 'no' sometimes; and de legating where possible.Following the decision in Walker, employers clearly have a responsibility for encouraging an understanding of what stress is and how it can manifest itself.

It has to be recognised as an acceptable part of the workplace, but there is a duty upon employers to take steps to minimise the levels of stress.

Employers should try to improve communication at the workplace and encourage colleagues at all levels.

Staff should be encouraged to maximise their potential through relevant training and development programmes.

Employers should encourage staff attendance at workshops or courses that assist staff to reduce work pressures.

Pressures of work will not go away, but a good basis of employment relationship demands that employers should understand the needs and concerns of employees who may be subjected to high levels of stress, and to take steps to minimise the risk of mental injury and, consequently, loss of job satisfaction.