LONDON - Health Secretary Alan Johnson will call on retailers and food producers on Wednesday to end a split over health labels on food and agree to a single scheme to help tackle obesity.

"I am determined that we must see the adoption of a single labelling system based on the best available evidence," Johnson is expected to say as he launches a government strategy to reverse rising obesity levels.

The government says two thirds of adults are either obese or overweight and on current trends this could climb to nine in 10 by 2050.

But Johnson's plea looks set to fall on deaf ears after Tesco said it would be sticking with its preferred food labelling system.

The government says attempts to promote healthy eating have been confused by a food industry schism last year over labels used to show levels of salt, sugar and fat.

The industry is divided between a three-colour "traffic light" system, promoted by the Food Standards Agency watchdog, and one supported by Tesco that uses guideline daily amounts (GDAs).

Johnson is expected to say he wants the food industry to unify around an independent review of food labelling, announced by the Food Standards Agency (FSA) last week.

The government hopes it will be difficult for retailers and manufacturers to go against the review's recommendations on a single labelling scheme when it reports in December.

But Tesco, whose chairman David Reid is a member of an industry committee supporting the FSA review, said it would not be abandoning its preferred GDA labelling.

"We believe obesity to be one of the most pressing public health issues of our time," said a Tesco spokesman.

"This is why we have pioneered simple, front-of-pack GDA labelling which now appears on some 20,000 products.

"We know this scheme is changing eating habits for the better and so we cannot honestly agree to an unproven FSA scheme which can only be used on a much narrower range of products."

Supermarkets J.Sainsbury, Wal-Mart's Asda and Marks & Spencer have all embraced variants of the FSA's red-amber-green system.

But Tesco rejected the traffic light scheme, which puts red labels on sugary and high fat foods.

The supermarket, along with Cadbury Schweppes and Coca Cola, opted for the uncoloured GDA system which shows sugar, salt and fat levels as a percentage of recommended daily intake.