UK food manufacturers and retailers, including Cadbury Schweppes, Coca-Cola and Tesco, are mounting a further challenge to the Food Standards Agency's official nutritional labelling scheme through the launch of a GBP4m (US$7.78m) campaign to promote the labelling of guideline daily amounts.

The GDA campaign will begin on 8 January, with a series of television and print advertisements.

Food manufacturers involved in campaign to promote GDA labelling have rejected the 'traffic light' scheme put forward by the FSA, fearing that consumers will not buy products with the red warning label, meaning that the product is high in fat, salt or sugar and should not be consumed in excess. The alternative labelling proposed by the industry shows GDA percentages of sugar, salt, fat and calories contained in each serving.

However, the food manufacturers and retailers claim that they are not motivated by fear of the negative impact the traffic lights system could have on sales. According to the supporters of GDA labelling, consumers find GDA percentages easier to understand than the traffic lights alternative.

"This isn't just about a label, it's about a lifestyle. We have made it simple to compare what's inside thousands of every-day foods so you can choose what best suits your diet," said GDA campaign director Jane Holdsworth in a statement.

On the other hand, the FSA has produced research in support of the traffic lights scheme, which it claims is easier to understand. "Some consumers do like the extra information that GDAs provide," it said in a statement. "However, without a traffic light colour code our research showed that shoppers can't always interpret the information quickly and often find percentages difficult to understand and use."