Tesco is to test putting carbon labels on its own brand varieties of potatoes in a move to allow customers to choose products which are less damaging to the environment.

The labels will identify how much carbon dioxide, as well as other greenhouse gases, are produced during the production and consumption of potatoes.

If they are successful, the labels, which are also being tested on other own brand products including light bulbs and orange juice, will be put on all of Tesco's products within five years.

The supermarket claimed it would be the first supermarket in the world to introduce the labelling, which it has worked on with the Carbon Trust.

A major step

Tesco boss Sir Terry Leahy said carbon labelling was a "major step".

"We want to give our customers the power to make informed green choices for their weekly shop and enlist their help in working towards a revolution in green consumption," he said.

Michelle Waterman, Tesco agricultural manager, said the supermarket had also run a carbon measuring trial with beef farmers, but it wasn't ready to introduce labelling on its beef products yet.

"It's quite hard because we have 10,000 beef farmers and each is different," she said.

"We said from the beginning introducing carbon labelling is going to be a big and complex work, but that doesn't mean we shouldn't try."