P was a bus company that bought out some rivals. The Commission was entitled to hold an investigation into a company if, under the Fair Trading Act, the area concerned was a “substantial part of the United Kingdom”. The commission investigated P, interpreting “substantial” to mean something “more than merely nominal”. HL held that this was a correct interpretation and therefore there were no grounds for judicial review.
Lord Mustill: Unclear judgment (B,M&E): At one point he suggests that if the commission got the meaning broadly right then the courts wouldn’t interfere, suggesting that jurisdiction isn’t hard-edged. He seemed to say that the court could only overturn the interpretation of the commission if it was not one of a range of acceptable interpretations.
