A technical hitch could delay the implementation of new European rules on the labelling of foods with nutritional claims by re-opening a debate on nutrient profiling.

The European Nutrition and Health Claims Regulation, which will control on-pack nutritional health claims, was due to come into force in September. However, because of a procedural problem it could now be held up for months.

The sticking point is that the regulation contains a legislative mechanism that has since been superseded by another. The original mechanism - known as a 'comitology' procedure - permitted changes to the regulation after adoption without the need for a lengthy examination by the European Council of Ministers and Parliament.

This was included after disagreement over nutrient profiling, and whether products containing high levels of certain components should be allowed to carry health claims. The Parliament favoured a tough stance on products high in fat, sugar and salt, while the Council preferred a less restrictive approach.

In May a compromise was reached that a food could carry a claim - such as "low fat" or "high fibre" - providing that it breached the set profile for only one of salt, sugar and fat.

In addition, if a product carried a nutritional claim, but was high in either salt, fat or sugar, it would have to declare this on pack. This could affect products such as yoghurt, which are often low in fat but high in sugar.

The nutritional profiling limit was to be set within two years through the comitology procedure by the Standing Committee on the Food Chain and Animal Health. But in a move to increase the accountability of standing committees, the Commission replaced the procedure in July with a system under which Parliament can intervene.

Ed Komorowski, technical director at Dairy UK, warned that delays could ensue if Parliament believed the committee was not acting in consumers' best interests. "If it reopens the debate on nutrient ­profiling, a long delay could result," he said.