Could you please tell me if anyone breeds American Staffordshire terriers in the UK?

I don't think that there are any (I'm sure that someone will correct me if I'm wrong). I also think that they are not allowed in ENgland. There was a wonderful one that one at the World Show last week and it was an English judge who placed him.

They are not a banned breed in this country (UK) and there is nothing to stop one being imported at the current time.(although why any one would want to is another topic!!)

Sam is right.
They are not banned in the UK and there are a few here, but I have no idea how you would go about finding a breeder.
If you really want one, then maybe Europe is probably your best bet. They are very popular there :-)

Hesitate to say this, but run a search on Exchange and Mart, (I do it regularly to check if the situation in Flatcoats is still healthy, if you get my drift.) I have seen American Staffords advertised there, but obviously can't say anything about their credentials.

Jo and the Casblaidd Flatcoats