Research has prompted claims firms such as Mars, Haribo and PepsiCo are in ‘flagrant’ breach of codes of behaviour

Most TV adverts for sweets, crisps and chocolate shown when children are likely to be watching are placed by firms who claim not to promote their products to that age group.

The disclosure, in new research by the University of Liverpool, has prompted claims that food giants such as Mars, Haribo and PepsiCo are in “flagrant” breach of their own codes of behaviour.