Many supermarkets claim to be green, but how much of that is marketing and how much is ingrained in their overall policies?

The National Consumer Council (NCC) carried out research into the environmentally-friendly credentials of the major supermarket chains, taking into account standards on transport, waste and sustainable farming.

How the chains rated: ASDA - food transport B, waste E, sustainable farming D, overall D Co-op - food transport C, waste D, sustainable farming C, overall D M&S - food transport D, waste D, sustainable farming C, overall C Morrisons - food transport D, waste E, sustainable farming D, overall E Sainsbury s food transport D, waste C, sustainable farming B, overall C Somerfield - food transport C, waste E, sustainable farming E, overall E Tesc o - food transport D, waste C, sustainable farming C, overall D Waitros - food transport C, waste C, sustainable farming B, overall B.

Chairman of the NCC Lord Whitty said: "Food is the typical household s number one contributor to climate change.

"By throwing away ten billion carrier bags each year and transporting carrots from Egypt and strawberries from New Zealand, we hit the environment hard."

*Supermarkets rated A (good) to E (poor)