Marks & Spencer has finally nailed its colours to the mast in the front-of-pack signpost labelling debate, revealing plans to pilot, er, both.

From January, a combination of traffic lights and Guideline Daily Amounts will be introduced to its M&S Count on Us and Italian ranges, as well as all of the 100-plus products in its healthy non-diet ready meals range, M&S Eat Well Nutritionally Balanced, launched last month.

The pilot will be nationwide and, if deemed a success in the first few months, will be rolled out across other ranges.

The move is something of a u-turn for the retailer. In July, Stuart Rose, chief executive, hinted to The Grocer he did not favour traffic lights, saying: "There's value in educating consumers. But do you really want to see red traffic lights all over a natural food because of what it contains?"

But customers had requested additional nutritional information, said Marks & Spencer this week, and the products will now carry green, amber or red colour-coded indicators for calorie, sugar, fat, saturated fat and salt content. "Our approach not only provides consumers with at-a-glance front-of-pack nutritional information, but also sets a new standard by combining this with percentage Guideline Daily Amounts," said Guy Farrant, director

of food.

M&S joins Asda and McCain Foods in introducing a combination approach. Kettle Foods has also chosen a combination, but for back-of-pack labels until an industry consensus is reached.

The Co-operative Group, Sainsbury's and Waitrose are backing the Food Standards Agency's recommended traffic lights scheme, while a number of retailers and manufacturers, including Morrisons, Kellogg and Nestlé, have chosen to adopt the Tesco-developed GDA scheme favoured by the Food and Drink Federation.

The Food Standards Agency welcomed the M&S decision.

"It is significant that such an influential retailer of own brand products recognises how effective traffic light front-of-pack labelling can be in helping people understand and make healthier food choices," said a spokeswoman.