Expired warning led to unfair dismissal

The Court of Session has held that an employer cannot rely on an expired warning when deciding whether to dismiss an employee.

Morris Thomson, an operator in a pharmaceutical firm, was dismissed after failing to carry out a safety process — a failure that had potentially fatal results.

His employer took into account the fact that he had already received a written warning for the same misconduct, even though the warning had already expired.

The court held that it is is against the principle of fairness for an employer to put a time limit on a warning and then take it into account as a factor in a decision to dismiss after the expiry date.

The written warning was found to have played a crucial part in Thomson’s dismissal, since 17 other operators guilty of the same failure had not been not dismissed. His dismissal was therefore unfair.

Diosynth Ltd v Morris Thomson [2006] CSIH 5