The Department of Health has dealt a blow to the dairy industry by suggesting its new front-of-pack labelling scheme is unlikely to differentiate between natural and added sugars.

Dairy products naturally contain the sugar lactose. The industry is concerned the new voluntary traffic light system - which will come in later this year and give foods green, amber or red lights based on their sugar, fat, salt and calorie content - will make it impossible for its products to qualify for a green light even when they contain no added sugar.

The Provision Trade Federation wrote to the DH late last year, asking it to assess dairy products on the basis of added sugars only.

But in its response last week, the DH said it had sought advice from its lawyers and the EC and was against the idea. “We are considering our position, but it is likely that any labelling scheme will need to be based on total sugar,” it said.

PTF director-general Clare Cheney said dairy companies would be “very disappointed” if a total sugar approach were adopted. The dairy industry was also concerned about receiving high fat and satfat ratings under the scheme, but the sugar issue was worse, she said. “People expect dairy products to contain fat, but to be told there’s sugar in your milk will be extremely confusing.”

A spokesman for Dairy UK warned “this could dissuade the public from consuming milk and dairy products.” The issue also affected fruit juice, which contained fructose, he added.

However, the DH said some retailers were already using traffic lights on yoghurts and “we are not aware of any evidence that an amber coding on sugar has deterred consumers from eating dairy.” suppliers are expected to have the option of saying “contains naturally occurring sugar” on packs.