British advertising regulators have been accused of failing to protect children from aggressive marketing by food firms using internet games and online ads.
The Children's Food Campaign has called on ministers to introduce statutory regulation to close loopholes allowing ads banned from children's television to be shown on manufacturers' own child-friendly websites.
The campaign is supported by the British Medical Association, Diabetes UK and the National Obesity Forum. It wants limits on embedded online games such as the Haribo Super Mix challenge, in which children are encouraged to collect sweets, or the Chewits Taste Adventure, where they have to find sweets hidden in British landmarks.
Singling out websites for Cadbury, Swizzels Matlow, Oreo and other brands, it said self-regulation by the advertising industry is failing and warned that the internet has become an important battleground for children's diets.
"Food companies continue to exploit loopholes and advertise junk foods to children online, even though stronger broadcasting regulations prevent such advertising on children's television," said Malcolm Clark, co-ordinator of the campaign. "The Advertising Standards Authority [ASA] is struggling to get to grips with its new role and is failing."
The ASA said there was no evidence yet that any significant reform was needed, although it has launched a review.