"Has anyone ever totted up number of agencies, local and governmental, that can walk into retail food premises and demand to interview staff, inspect premises, records, and all sorts of books, and so on?"
Well, let me think... There are VAT inspectors, income tax officials, Customs & Excise, Border Agency, trading standards officers, environmental health officers, police (of course), 'Scores on the doors' (National Hygiene Rating Inspection), building inspectors, 'mystery shoppers' from various terminal providers such as Camelot and PayPoint, representatives of the Performing Right Society and PPL, and TV Licensing. That's an unlucky 13 off the top of my head. Forecourt traders have another additional set of inspectors to cope with due to the hazardous nature of their product.
The Home Office admitted (December 2009) that 1,043 different laws permit state inspectors (such as gas and electricity) to enter people's homes and premises.
As I said to Jim, if you dissect those thousand-plus laws, you'll probably find that (and I really don't have the statistic) the TSOs and EHOs are responsible for upholding several dozen each. So the law tally is huge, the inspectorate smaller.
By the way, it was rumoured that the Labour Party was about to allow debt collectors the right to enter premises when they got voted out, which could potentially have added more.
I also suggested to Jim that we ask readers to add to this list as I know there must be more and, in a perverse way, this could be fun. If you have a ludicrous one on your list, do share.