Ministers have published a green paper suggesting that a milkshake tax “may” be introduced - just hours before the likely election of a Prime Minister opposed to such levies.

A long-awaited green paper on prevention of ill-health was published on Monday night, without fanfare, setting out a host of policies aimed at tackling causes of ill-health.

The cautiously-worded, 78 page document suggests such taxes "may" be extended to sugary milk drinks, if the food industry does not make enough progress cutting the sugar content of common drinks.

The timing of the report - just hours before Boris Johnson is expected to be elected as Tory leader, and without any public backing from the Health Secretary - provoked scepticism about what will become of such measures.

Mr Johnson recently vowed to end the “continuing creep of the nanny state” if he becomes prime minister, starting with a review of so-called “sin taxes” on sugary, salty and fatty foods.