Mr Red:
Funnily enough, Fiascos and Painsbury's have bins to put them in, and are well used. In Stroud only it would seem. Famed for its alternativeness.

Cardiff as well (at least in the larger stores). Tesco claim to have them in many stores: To help our customers recycle, we have recycling stations in many of our UK stores including front of store recycling for carrier bags. We have recently extended this particular service to allow films of the same material type (polyethylene) to be added, for example bread bags. A new logo has been introduced which can be found on bread bags and bags used for frozen products so our customers know what they can recycle at our stores.