The National Obesity Forum believes that the 20% levy recommended by Public Health England and championed by a number of chefs, politicians and health bodies would be ‘insufficient’.

Professor David Haslam, chairman of the NOF, told The Independent: “Anything less than a 50 per cent tax on sugary drinks will be insufficient as a disincentive to consumers. 

“We don’t currently support taxing food products… but sugary drinks have no place in anyone’s diet.”

The 50% tax would mean a 330ml bottle of an added-sugar drink, such as Coca Cola or Pepsi, would rise from 99p to £1.49.

Prime Minister David Cameron recently didn’t rule out the possibility of introducing a sugar tax as he said that Britain needs a ‘fully worked-up programme’ to deal with the obesity problem.

He said: “I don't really want to put new taxes on anything but we do have to recognise that we face potentially in Britain something of an obesity crisis when we look at the effect of obesity not just on diabetes but the effect on heart disease, potentially on cancer, when we look at the costs on the NHS, the life-shortening potential of these problems.”

The Government is expected to release its obesity strategy later this year.