Gross misconduct is behaviour by an employee which is so poor, so disgraceful, that the employer cannot be expected to employ him or her any more. The behaviour must be a fundamental breach of the employment contract (the contract can be written or oral). This means a breach of contract which “goes to the heart of the contract”.
The employee’s conduct must be incompatible with the employee’s duties of fidelity, trust and confidence. The act could be one of dishonesty, or an action intended to damage the employer’s standing.
Gross misconduct must be so heinous that it is fair to dismiss the employee without giving any warnings, or even opportunities to improve.
It will be much easier for an employer to prove gross misconduct where the misconduct is listed as grounds for summary dismissal in the employment contract, or disciplinary rules, and/or staff manual.
With some jobs, it will be essential for the employer to list actions or omissions, particular to that industry, which have serious consequences, such as a breach of food hygiene standards in a restaurant kitchen.