Labelling is really a red herring, side-tracking us from the priority of getting genetically engineered foods off supermarket shelves and preventing them from contaminating the food chain.
Having said that, while this contamination persists, there is an obligation on politicians, food processors and supermarkets to label products very clearly. Not to do so, amounts to force-feeding people with food they have clearly rejected, as demonstated in every known poll.
Indicating the presence of GM material in the ingredients lists is worthless. Almost nobody has the time to inspect the ingredients list of every product they want to buy when filling a trolley with a week's groceries. You might pick up 5 or more packets of biscuits before finding one that is GM-free. Those with less than perfect eyesight will have problems. Old people may struggle to do their shopping at all, so this system discriminates against them too.
Food shopping for most of us anxious to avoid GM material, has changed from a chore to a time consuming nightmare, a veritable minefield for the unwary. Nothing less than a very clear label or symbol of decent size proportional to the size of the packaging, giving 'at-a-glance' recognition, will be acceptable.
All we want to know is if the product is:
1) Guaranteed free of genetically modified material.
2) NOT guaranteed free of genetically modified material.
A third option of "may contain GM" is irrelevant and meaningless.
Most important is that the definition of "GM-free" is "free of ALL genetically modified material", including oils, lecithin etc, derived from GM crops.
Some supermarkets are now moving towards eliminating all GM content from their 'own label' products. Pressure them into doing this as a matter of urgency. It will mean that you can at least choose 'own label' products without the hassle of checking every ingredients list.
Some food processors like Unilever and Nestle are still actively promoting
biotechnology for food and contaminating their products with GM ingredients
unnecessarily, apparently abandoning the normal way of doing business, which is
to provide the consumer with what he/she wants.
(Pressure on Unilever in Germany resulted in GM ingredients being removed from their products over there)
Unsurprisingly they don't want to label clearly, anticipating an inevitable drop in sales. Maximum pressure is vital to change their policies.