O’Connell was employed at a branch of Marks and Spencer PLC. The staff regulations provided that smoking was allowed only in the staff lounge and the roof garden during specified hours and that there must be no smoking at any time in any other area of the store, including the yard and the perimeter of the store. It was expressly stated that failure to comply with the regulations would result in summary dismissal. O’Connell was on duty one night on a 12-hour shift with responsibility for ensuring that members of the public did not enter the premises and that contractors, working on new escalators, did not smoke inside the store.

During the course of his shift, O’Connell was observed smoking on the tiled area in front of the store. An investigation was conducted and he admitted that he had deliberately breached the smoking policy. He was instantly dismissed. On bringing a claim for unfair dismissal, the tribunal found that the employers had carried out a reasonable investigation and had a genuine belief that O’Connell had breached the serious safety regulation. However, evidence was given that contractors had no restrictions on smoking in the same area, nor did members of the public and, additionally, O’Connell had little opportunity to take a break. The tribunal also heard that the smoking ban was not total but one selectively applied for safety purposes to prevent fire hazards. They decided, given all the evidence, that dismissal was not a reasonable response and that the dismissal was unfair. The employers took the case to appeal.