Food campaigners have called for tighter regulations on the amount of water found in processed meats sold in Britain.

The Food Commission is pressing the Food Standards Agency for tougher laws on labelling.

Manufacturers are allowed to add 5% extra water to processed meat without declaring it in the ingredients and 10% extra in uncooked meats.

The Food Commission claims that some processed meats sold in supermarkets contain as little as 37% meat as companies are not bound to reveal the full extent of “added water”.

It highlighted several products from Bernard Matthews including its Wafer Thin Turkey Ham, which contains 60% meat as well as supermarket own-brand products. Asda’ Traditional style Irish recipe sausages contain just 37% meat.

A spokesman for the Food and Drink Federation defending the industry said: “Added water can be an essential part of the production process and can be necessary to retain flavours and succulence to ensure that the product is acceptable to consumers.”