Local government co-ordinator Lacors is to lobby for a tightening of the tolerances allowed for nutrition declarations.

At present a margin of error of 20% is allowed between what is said on pack and what is contained in the food. But Lacors said it believed this was too generous and would call on Brussels to lower it.

"People have a right to know how healthy their food is and it's absolutely vital that accurate nutritional information is provided on food packaging," said Geoffrey Theobald, Lacors chairman. "Brussels is currently reviewing the legislation that covers food labelling and Lacors will be calling for tougher rules."

Lacors' comments came in the wake of a Channel 4 Dispatches programme, The Truth About Your Food, which claimed nutritional information on the packaging of some convenience foods was "grossly inaccurate". The programme's researchers said some products tested exceeded the maximum margin for error by as much as 65%.