The cornerstone of the law around dismissal for misconduct is twofold. The reasonableness of a dismissal for misconduct will depend first on the fairness, or otherwise, of the investigation into the alleged misconduct and secondly on the treatment of that misconduct as a sufficient reason for dismissal. The late 1970s case of British Home Stores v. Burchell remains authority for the proposition that a misconduct dismissal will only be fair if, at the time of the dismissal, the employer believed the employee to be guilty of misconduct; it had reasonable grounds for that belief; and, at the time it held that belief, it had carried out a reasonable investigation. 

In recent months, two misconduct cases have considered whether serious misconduct or a series of acts of misconduct can warrant dismissal. 

In Quintiles Commercial UK Ltd v. Barongo, the employee was subjected to disciplinary proceedings for two acts of misconduct: first, failing to complete an online compliance training course by a particular deadline; and, secondly, failing to attend a compulsory training course. Although the employee was undergoing a performance improvement plan, he had received no previous warnings. The employee's reasons for failing to take part in both training courses were not accepted and he was dismissed for gross misconduct. On appeal, whilst the appeal chair was prepared to accept that the misconduct was "serious" rather than "gross", the dismissal still stood (and therefore notice was paid). 

In the first instance, the employee was successful in persuading an Employment Tribunal (ET) that he had been unfairly dismissed. The ET focused on the change in label from "gross misconduct" to "serious misconduct" and found that, coupled with a clean record, serious misconduct should not lead to dismissal. The Employment Appeal Tribunal (EAT) ultimately disagreed, finding that dismissal is not rendered automatically unfair if the conduct properly falls to be categorised as something less than gross misconduct. It is capable of being a fair dismissal provided it is for a reason relating to the employee's conduct. The ET was also found to have mistakenly substituted its own view for that of the employer (that a warning should have been given).

In the second case of Mbubaegbu v. Homerton University Hospital NHS Foundation Trust, the employee (who had an untarnished disciplinary record across his 15 years of employment with the Trust as a consultant orthopaedic surgeon) faced serious allegations of a breach of "Department Rules and Responsibilities". During the investigation into these initial allegations, the Trust uncovered a further 22 allegations of misconduct. The employee was subsequently dismissed for gross misconduct. In a majority decision by the ET (one of the lay members disagreed on the basis of the "trivial" nature of some of the allegations) it was found that the dismissal of the employee was fair as he could not be relied upon to change his behaviour in the future and the decision to dismiss was within the range of reasonable responses open to the Trust. On appeal, the EAT held that "there is no authority to suggest that there must be a single act amounting to gross misconduct before summary dismissal would be justifiable or that it is impermissible to rely upon a series of acts, none of which would, by themselves, justify summary dismissal". Important to this decision had been the disciplinary panel's findings that there had been a wilful pattern of unsafe practices by the employee, which amounted to a real concern that a final written warning would not have been sufficient. 

These cases serve as a reminder that the black letter of employment legislation does not differentiate between the varying degrees of misconduct and the appropriateness of dismissal. Nevertheless, employers should proceed with some caution before reaching a decision to dismiss an employee with no prior warnings where there is no distinct act of gross misconduct. In these cases, both dismissals were ultimately found to have been fair; however, this will not be so in every case.