Sainsbury’s has criticised Tesco’s new WeightWatchers-style healthy eating initiative, claiming it will confuse shoppers trying to get used to the government’s new front-of-pack labelling scheme.

Tesco rolled out a range of 130 new products across 50 stores in London this week, with products colour-coded according to five different calorie bands.

But Sainsbury’s said the new initiative risked confusing customers.

“All the major multiples made a commitment to a clearer, unified approach to front-of-pack labelling so it is ­baffling to see why Tesco would introduce an additional, arbitrary form of colour coding for calories, especially additional labelling based on portion whereas front-of-pack calorie labelling is done on a per 100g basis,” said a Sainsbury’s spokeswoman.

A Tesco spokeswoman said: “Our fantastic new range is 100% based on what customers told us they wanted, including clear, colour-coded packaging based on calories. We did our research very carefully. Perhaps Sainsbury’s might like to suggest the right colour for sour grapes.”