Thank you Lastlid, I am also familiar with the Health & Safety at Work Act 1974 and the Management of H&S at Work Regulations.
Tesco's has a duty of care to it's staff, customers and visitors and must provide safe access and egress on their premises with suitable risk assessments in place. Any cases of breach will normally be brought by the Environmental Health Dept/ or the HSE, rather than by individuals but there has to be liaison with the local regulator before that happens. The case is being pursued by Environmental Health.