Health experts are calling for a 7p-a-can ‘fat tax’ on sugary soft drinks to tackle the rising menace of childhood obesity.

A powerful alliance of 61 organisations, including the country’s most eminent doctors and the Royal Society for Public Health, wants the move to be announced in the spring Budget.

The experts argue that the 20p-a-litre levy on bottles and cans of fizzy drinks could help cut consumption in the same way that tax is used to deter smoking and drinking.