Streetlife

I don't know of any legislation regarding "Locally Sourced Ingredients" - it is very ambiguous. As you say, anything purchased in a local supermarket could then be advertised as "Locally Sourced" and I have, infact, seen cooks from various town centre establishments buying vast quantities of items in the Co-Op that their kitchen has obviously run short on. 

Now "Locally Produced" is a dfferent matter but, how could it be disproved?

It can be very misleading but is all part and parcel of the 'tourist' environment.

An annoying experience I had last year when I wanted some fruit scones from the Co-Op - the shelf was empty and when I asked the manager if there were any 'upstairs' - he told me that all the fresh stock had been put out earlier but a local cafe/tea room had bought the lot for their cream teas!!!

When you visit one of the big 'cash and carry' warehouses it becomes clear where most cafe/catering food comes from!

I am not saying there is anything wrong with it at all unless you are claiming it is homecooked, but the huge catering packs of everything from gateaux to pies to stews really opens your eyes.

Presumably it is a Trading Standards issue if people are claiming Locally Produced, but as you say Bill Locally Sourced is a different matter. Misleading and immoral yes, illegal no.

It is very ambiguous. It is also unrealistic to say you use 100% locally produced items. We try (Selleys) to buy the majority of our ingredients locally and we never use cash and carrys. Our bread is from Upper Crust, Veg from the Market or Winchester's, Crab from Market fish etc. You could argue then that the tomatoes from Winchesters are not locally produced but at least we are committed to buying from a local store, even if we have to buy the odd item from a supermarket sometimes. We are Taste of the West members and as such we have to prove that we use products and companies in this area, even our Beers & Ciders are from Devon and our coffee locally roasted.
If someone is claiming something is homemade (there are a few) and its not, report them to trading standards.