The Food Standards Agency has admitted it could still lobby Brussels for compulsory traffic light labelling.

The agency launched its consultation on the European Commission's new food labelling regulation this week.

The commission has proposed obligatory front-of-pack labelling based on GDAs and has ruled out forcing companies to use multiple traffic lights.

A spokeswoman for the FSA, which currently recommends traffic lights, said: "The UK's position in negotiations will be informed by the responses we receive to our public consultation. The results of our independent research will also help inform our negotiations."

Responses to the FSA consultation are likely to be mixed, with the food industry split over the best form of labelling.

This means the FSA's final decision is likely to rest on the results of the research project, now under way, with results expected at the end of the year. The FDF-backed GDA Campaign insisted it was not concerned by this because it was confident the research would show GDAs were effective.

A recent survey of 560 Daily Mirror readers found 90% had seen GDA labelling and 63% had used it.

But even though Brussels has come out in support of front-of-pack GDAs, there is uncertainty over whether suppliers and retailers will be forced to present them on a 100g/100ml portion basis. That would dismay some supporters of GDAs - particularly those that make products such as cereals and spreads, which are normally eaten in far smaller portions.

Products packed on an individual portion basis may use per-portion GDAs alone, the regulation states, suggesting products not packed as individual portions will have to carry GDAs based on a 100g/ 100ml serving.

But the regulation also states: "The expression on a per portion basis alone for foods presented in packages containing multiple portions of food that have not been prepacked as individual portions shall be established by the commission."

This would appear to say per-portion GDAs alone will be permitted for all products, after all.