Tesco has been accused of publishing misleading figures claiming it had hit targets for plastic bag reduction.

Supermarkets, including Tesco, Sainsbury’s, Asda and Marks & Spencer, had all signed an agreement to cut the number of plastic bags used by 50 per cent in the three years to this May. They collectively just missed this target achieving a 48 per cent reduction, which was reported via the Waste and Resources Action Programme (Wrap).

That day Tesco put out a statement which said: “Our customers are now using more than 50 per cent fewer carrier bags than they did before.”

However The Times reports that when questioned on this figure the supermarket admitted that its figure was calculated in a different way to the one it gave Wrap to issue,. It said that figures had been adjusted to account for growth in sales. The actual reduction, a senior Tesco source told the newspaper, was significantly less than 50 per cent.

A Tesco spokesman said: “In working out how many carrier bags our customers are saving, it is misleading simply to compare the overall number of bags issued now with those issued in 2006.”

He added: “More customers now shop with Tesco than did in 2006, and on average each is using 50% fewer bags than they did then. This is the most meaningful number. We believe this is a huge achievement in three years.”

Last week Tesco hit its target of diverting 100 per cent of its UK waste away from landfill a year ahead of schedule.