jats:titleAbstract</jats:title>jats:pThe impact of H.L.A. Hart'sjats:italicThe Concept of Law</jats:italic>on modern legal thinking is undisputed. But does it reflect the reality of the way British institutions work? Injats:italicConcept,</jats:italic>Hart argued, amongst other things, that one of two ‘minimum conditions necessary and sufficient for the existence of a legal system’ was that ‘its rules of recognition specifying the criteria of legal validity and its rules of change and adjudication must be effectively accepted as common public standards of official behaviour by its officials’. In this paper, we begin the process of testing that statement empirically. Specifically, we ask whether non-judicial UK officials have a uniform view of what the rules of recognition, change and adjudication are, and whether they uniformly take an internal point of view towards them (i.e. whether they accept the rules and do not merely obey them). By way of a pilot study, thirty non-judicial UK officials were interviewed. Those officials comprised currently serving and retired senior civil servants, senior military officials, chief constables and local authority chief executives. The findings of the pilot study are presented in this paper. They allow us to deduce that Hart's statement might well be an inaccurate and incomplete description of the modern British constitution, and to comment on the implications of that conclusion.</jats:p>