If you are after smaller quantities, try your local supermarket - both Sainsbury and Tesco definitely stock it. If you want industrial quantities, thry querying with local caterers to find out their suppliers
That's a pretty rude response to someone trying to help.
You didn't say American sour cream.
You seem to think there is a diference between sour cream and soured cream. They're the same thing. However American sour cream sometimes has added buttermilk and sugar to suit their tastes. Both are basically ordinary cream with lactic acid added.
Sorry, but I wasn't being rude, simply clarifying my question. And sorry again, but soured cream isn't the same thing, in consistency or taste. Mexican restaurants in the UK get it from somewhere and I was just hoping to find out from where. Oh well, c'est la vie!
As I mentioned in my first post - if you are desperate you should contact a local Mexican resaurant - try the Yellow Pages - and ask them where they get their stock from or, as is often the case with one-off restaurants, they may be willin gto sell you a quantity from their own kitchens.