Restaurateurs are furious that the Ministry of Agriculture - which only sent out guidance on how the complicated new laws will work three weeks ago - has not given them long enough to implement them.
Only a tiny proportion of restaurants, cafes and pubs are ready to meet the Ministry's 19 September deadline for identifying GM ingredients in food that is eaten out.
Restaurateurs believe the rules are unenforceable and will lead to chaos in the restaurant sector.
Eateries will face a fine if they cannot tell a customer whether a meal, snack or even a bread roll contains genetically modified soya or maize.
"It's a waste of space. It's a nonsense unless we can rely on our suppliers," said Mr Worrall Thompson. "This is a knee-jerk reaction from the Government.
"It's unenforceable. They haven't got enough environmental health inspectors or trading standards officers to check in the first place."
Trading standards officers privately say that they do not have enough officers to check whether restaurants are correctly labelling their meals. They say most restaurants are completely unaware the new laws are coming into force.
"It's going to be hugely difficult to implement this. The best we can do is to raise awareness," said Paul Galland, chief trading standards officer at Gloucestershire Council.Reuse content