Tesco will put carbon footprint labels on more products if it can overcome consumer confusion over carbon scores.

Customers need to be educated about why certain products have higher scores than others, said Tesco technical packaging manager Stephen Pizer.

"Where one product is sourced locally and one overseas, the instinct is that the one from overseas should have a higher carbon footprint," he said. "That might not be the case, however, because less heating or lighting might be needed to grow it.

"We have been doing some more work on the carbon footprint on some various types of product. We are now working on how we would roll it out."

Meanwhile, the Govern­ment has been called on to introduce a single environmental label backed up with clear criteria. In a report published this week, the Environ­mental Audit Committee said insubstantial and meaningless environmental claims are a growing problem.

"We urgently need a universal scheme to help consumers discriminate between products on the basis of environmental factors," said Colin Challen MP, who chairs the environmental information sub-committee. "A robust labelling regime would change the way many businesses behave and help drive up environmental standards across whole sectors of the economy."