Tesco and Sainsbury have drawn battle lines over traffic light labelling with both using high-profile advertising to state their opposing cases.

Tesco has been forced to defend its decision to press ahead with guideline daily amounts instead of the Food Standards Agency's multiple traffic light system, after it was accused of not wanting to tell people what is in its food.

Members of the Women's Institute had been encouraged to visit stores to vent their frustration over Tesco's decision to go against the government, while championing Sainsbury's labelling, which is backed by the FSA. In retaliation, Tesco has been running a full-page advertisement, which appeared in all the national newspapers on Monday. The ad read: "Why all the hoo-hah of the last few days? Well, last week saw the launch of the traffic light system adopted by some other supermarkets. But not Tesco."

It added that while it had looked at traffic lights, research had shown that it was confusing to customers.

Meanwhile, Sainsbury has been running press ads to 'introduce a food label with a difference', although its FSA-backed Wheel Of Health traffic light system was actually launched 15 months ago.

A Sainsbury spokeswoman said the opportunity to raise the profile of its label was too great to pass up.

It said: "There's been such a renewed interest since the FSA put forward multiple traffic lights, and manufacturers have been adopting some sort of labelling of their own. The whole issue is now much more in people's minds than when we first launched Wheel of Health last year."