Coca-Cola Christmas Truck visits Tower Bridge's Potters Fields on December 2, 2015, London, England. [Photo/IC]

Former British Prime Minister David Cameron originally declared war on obesity and high-sugar content drinks, with plans for a "sugar tax."

The government's childhood obesity plan published Thursday, which proposes a voluntary target to cut sugar in children's food and drink, immediately generated widespread criticism.

The British Medical Association (BMA) representing Britain's doctors, said the government had "rowed back" on promises it had made to tackle obesity.

MP Sarah Wollaston who chairs the House of Commons health select committee, described the obesity plan as "really disappointing".

She said whole sections from the original draft have been dropped including measures on advertising junk food to children.

On earlier Thursday, government officials released a report on the proposed levy on soft drinks, the so-called sugar tax. The levy will make soft drinks companies pay a charge for drinks with added sugar, and total sugar content of five grams or more per 100 millilitres, about 5 percent sugar content. There is a higher charge for the drinks that contain eight grams or more per 100 millilitres.

The report said there are nine teaspoons of sugar in a 330 ml can of cola, instantly taking children above their recommended maximum for the day.

"A five year old should have no more than 19 grams of sugar in a day, but a typical can of cola can have 35 grams. Public health experts from the Chief Medical Officer to the British Heart Foundation agree that sugar-sweetened soft drinks are a major source of sugar for children and teenagers, and that sugar intake drives obesity."