A fizzy drinks tax is needed to tackle Britain's obesity crisis, Liberal Democrats will argue, as part of a major shake-up of the food and drink industry.
Baroness Parminter, the party's environment, food and rural affairs spokesman, is demanding state intervention to promote "healthy eating behaviour".
A motion to be debated at the party's conference later this month calls for "policies and measures aimed at promoting healthier and more sustainable diets, including consultation on fiscal measures such as the taxation of heavily sugared drinks".
Last year, a study in the British Journal of Nutrition argued a 10 per cent tax on sugar-sweetened drinks would cut consumption and improve health.
But the Lib Dem proposal has been criticised by the British Soft Drinks Association. A spokesman said: "A tax on soft drinks is not the way to fight obesity … While the incidence of obesity has increased in recent years, the consumption of calories from soft drinks has not increased and makes up only 2 per cent of the average diet."
Tax will form the main theme at the conference in Brighton, under the slogan Fairer Tax in Tough Times. While the main focus will be on the policy to raise the income tax threshold to £10,000, delegates are expected to back a tax on plastic bags to discourage their use – an idea thus far blocked by the Treasury.
A Lib Dem spokesman said: "These are proposals that will be considered and voted on by our members. There will no doubt be a healthy debate with strong arguments made for and against."