People with nut allergies are finding it increasingly difficult to buy food because of inconsistent and misleading product labelling, according to the Food Standards Agency.

The government-funded food watchdog commissioned research that found 71 of 127 normally nut-free everyday products were labelled as having a risk of trace contamination.

It said people were now questioning whether the food suppliers were using it defensively "to cover their backs".

In the early days, such labelling was considered responsible and helpful to allergic consumers

FSA

This "blanket insurance policy" severely restricted the choice of even the most basic of food items that people with a nut allergy could buy, it added.

Allergies to peanuts, hazelnuts and walnuts are among the most common. The smallest traces can trigger a fatal reaction.

Products whose ingredients may have been transported with nuts or made in the same factory as others could also pose a threat.

As a result food manufacturers and retailers increasingly label products with the vague warning: "May contain traces of nuts".

The FSA said: "In the early days, such labelling was considered responsible and helpful to allergic consumers.

Guidelines

"But as the range and number of products labelled in this way increased, consumers began to question whether the food suppliers were using it defensively 'to cover their backs'."

Head of allergy and food tolerance at the FSA Dr Catherine Boyle said: "Using 'may contain' as a blanket insurance policy has a real impact on nut allergy sufferers as they find their choice of even the most basic of food items significantly restricted."

She urged manufacturers to "re-examine the labels they are using in light of this report", adding the FSA would work closely with them to develop "practical and helpful" guidelines.