Discarded bags can kill small animals and birds
Efforts to cut by half the number of plastic carrier bags supermarkets give their customers have narrowly failed.
Last year seven supermarkets signed up to the voluntary scheme which aimed for a 50% cut in bags given out compared to figures recorded for 2006.
However figures suggest 346m fewer carrier bags are being used every month than they were in 2006.
Plastic bags harm the environment because they take a long time to decompose and can endanger wildlife.
In May 2006, 718m bags were being given out but by May 2009 this had almost halved to 372m, which amounts to a reduction of 48%.
In Scotland, the reduction was 49% representing 39m bags fewer in May 2009 compared with the same month in 2006.
Environment Secretary Hilary Benn said: "This is a great achievement by the seven supermarkets and their customers and it shows that by working together, we really can change our bag habits."
He praised retailers for putting a lot into the scheme, and said he was looking forward to further reductions in the months ahead.
Mr Benn added: "This means that several hundred million fewer carrier bags are going to landfill every month and we're using less raw materials to make them, which is great news."
The British Retail Consortium believes consumer behaviour has now changed, helped by supermarkets giving out free re-usable bags and awarding loyalty points to customers who bring their own bags.
As a result, some environmentalists are now calling for a charge of up to 15 pence for each disposable carrier bag.