Seriously some of you people on here are just plain moaning over nothing. We should follow France's lead and ban plastic bags full stop.
As long as they still offer a free alternative bag to carry my things in then go for it.
When we do a big family shop I'm not going to bring loads of bags with me, plus if I see something in a shop I like by chance I'm not likely to have a bag on my person.
Supermarkets used to have boxes available at the tills, I would quite happily use those instead. Or as suggested supermarkets should offer free environmentally friendly bags at the tills.
I don't see why the customer should lose out and be inconvenienced while supermarkets rip us off and wrap everything in plastic anyway.