Supermarkets are still in the dark about the ramifications of Ofcom's ruling on advertising junk food to children. The Ofcom decision to ban the advertising of all high fat, salt and sugar products during kids' programming, and its plan to extend that to any programme, at any time of day or night, that has particular appeal to under-16s, could have major implications for supermarkets.

Marks & Spencer's 'this is not just' chocolate pudding ad and Jamie Oliver's campaign featuring Sainsbury's Taste The Difference cheese would very likely fall foul of the regulation.

Both Sainsbury's and Marks & Spencer said they were currently waiting for clarification to discover what was acceptable.

Sainsbury's said: "The ruling was broadly in line with our expectations but we need clarification for Active Kids. We will also look at our scheduling and at what foods are going to be affected."