Environment Secretary David Milliband called together the bosses from the 'big four' supermarkets - Tesco, Sainsbury's, Asda and Morrison's - to impress on them the importance of becoming more environmentally friendly.

A sustained policy of cutting the food miles travelled by goods can only be good for local farmers and growers if it results in more supermarkets sourcing fresh produce from small, regional suppliers rather than importing from overseas.

The bad press surrounding the supermarkets on this issue is also beneficial to independent retailers who specialise in local fare. New figures released by Defra this week indicate that CO2 emissions caused by food transport are on the increase.

Commenting on the research, Liberal Democrat environment spokesman told The Guardian:

"Our own research has revealed that supermarket lorries travel the equivalent of almost four return trips to the moon every day.

"The big chains have a duty to provide environmentally friendly alternatives by supporting local producers."