Wall's is planning to use a protein originally isolated from fish blood to create the world's first ice creams using genetically-modified technology.

Its parent company, Unilever, claims the technique will allow it to develop low-calorie, low-fat ice creams. It could be used to create new versions of best-sellers such as Cornetto, Magnum and Carte D'Or.

But using GM technology may be at odds with a desire by consumers for a more natural 'real' food diet, where artificial additives are removed.

However, Unilever believes the benefits of low-fat ice cream could outweigh any doubts about GM.

The blood protein originally comes from the eel-like ocean pout fish, which uses it to survive extreme cold at the bottom of the seas.

The protein has been chemically sythensised and can be grown in vast vats which produce a brownish liquid. This is added to the ice cream and lowers the temperature at which ice crystals form and the shape they take up.

It is claimed a stiff and solid mixture can then be created by using less cream or fat.

An application to use the new technology, involving the GM process, has been lodged with the Food Standards Agency which is inviting comment.

Unilever said the process has already been approved in the U.S. and other parts of the world.

It stresses that no GM material remains in the final product, rather the process used to create the protein involves a GM element.

But Friends of the Earth food campaigner Clare Oxborrow said: 'At a time when more and more consumers want to choose unadulterated food, it's disappointing to see Unilever investing in this unnecessary development in overly processed food.'