At most, only one to three per cent of bags end up being recycled. Many are now shipped to India or China where, under more lax environmental regulations, they are burnt, often in waste-to-energy incinerators - the polyethylene in bags, when burned, gives off more energy than coal.

What of plastic bags which are recycled into plastic? They are reduced into tiny pellets, which may then be made into envelopes, drain pipes, wood-polymer lumber and more plastic bags.

Others end up in more fanciful and unexpected items. A Huddersfield manufacturer, Cutouts, makes them into coasters; in Manchester, the company Paperchase converts them into sheets of luxury multi-coloured paper (£8 each); in Nottingham, Bags2Riches turns them into designer cuffs (at £16.50 a pair) and necklaces (from £18.95).

Advances in America mean that plastic bags and water can now be made into cheap glasses, called Liquid Specs, to bring better sight to the impoverished in the developing world. Finally, the world's poor will be able to see whether that colourful item flapping from the branch of a tree is a bird or a bag.