A Royal Decree states that real mayonnaise should contain at least 80 per cent fat and 7.7 per cent yolk. This irritates Belgian producers in times when more people are thinking more about what they eat, with an increasing demand for light products.

"This situation is no longer tenable", explains Nicholas Courant as spokesman of the Belgian federation representing the food industry, Fevia. "Belgian manufacturers are suffering from unfair competition. Producers abroad don't have to follow these regulations. They can produce mayonnaise with less fat to meet the increasing demand for toppings and sauces containing fewer calories."

Belgian stores are now selling Spanish mayonnaise with only 65 per cent fat and Dutch mayonaise with 65 per cent fat. "If we want to sell the same type of mayonnaise in Belgium, we have to label it as 'salad dressing' which makes it less attractive", Belgian producers say.

Belgian topping suppliers want the 60-year-old legislation to be adapted, but consumers' organisations are afraid that this will harm the authentic recipe and the quality of Belgian mayonaise.

The Belgian minister responsible for Consumers' Affairs, Kris Peeters, is bringing the different parties together "after years of discussions" to work out a proposal to adapt present legislation. One solution would be to create two types of mayonnaise under Belgian law: 'traditional' mayonnaise (80% fat and 7.5% yoke) and 'normal' mayonnaise (70% fat and 5% yolk). A change would have no impact on the legal composition of Belgian mustard.