Calorie limits will be imposed on thousands of foods sold in supermarkets and restaurants in a bid to combat obesity.

Draft proposals seen by The Telegraph set out detailed caps for ready meals, sandwiches and even portions of vegetables served across the country.

The plans, drawn up by Public Health England (PHE), suggest a limit of 544 calories for any convenience meal - far below many of those sold today.

Sandwiches and main meal salads would be capped at 550 calories, with a limit of 951 calories for restaurant main courses, and varying limits for other specific foods depending on where they are consumed.

The efforts are part of a Government childhood obesity strategy which promises to cut the calories in common foods by a fifth by 2024.

But the detailed proposals have infuriated manufacturers - who say they are far too complex and confusing to be workable. Among the details are limits of 134 calories per vol-au-vent or onion bhaji, with a cap of 145 calories for salad dressing.

Critics said the plans were “insane, arbitrary and unscientific”.