The sugar tax will "hit poorest families hardest", campaigners claim. The Taxpayers' Alliance, who are working to axe the levy, say that the controversial sugar tax will place a burden on the poor, by charging taxes on fizzy drinks, which are consumed mainly by lower socio-economic subgroups.

They go on to say that sugary coffees and fruit smoothies enjoyed by the middle-classes will escape the sugar tax, and complain that the levy is being unfairly aimed at the poor.

A comparison of 49 different drinks revealed some coffees and smoothies contain more sugar than fizzy drinks. For example a Starbucks signature hot chocolate with whipped cream and coconut milk has 11 grams of sugar per 100 millilitres but is exempt from the tax, even though Coca-Cola, which has 10.6 grams per 100 millilitres, will be hit.

"It is deeply concerning that the Government has given in to the pressures from the public health lobby and is pushing ahead with this regressive tax which will hit the poorest families hardest. The evidence shows that the sugar tax has nothing to do with the sugar content of products, so it is farcical to suggest that this will have any positive impact on people's diet or lifestyle choices," TPA chief executive, Jonathan Isaby said.

The TPA claims wants the tax scrapped because it takes no account of the amount of sugar in drinks, as some beverages laden with sugar such as syrupy lattes and juices will be exempt.

Sugar Tax
Levy groups say that lattes sold in coffee shops which will not be taxed on sugar content, contain more sugar than fizzy drinks Justin Sullivan/Getty

Meanwhile, a Treasury spokesman said the soft drinks industry levy was "a major step forward in our efforts to tackle childhood obesity. The levy will be charged on soft drinks because they are the main source of added sugar in children's and teenagers' diets, many with no intrinsic nutritional value."

He said that treating obesity and its consequences costs the taxpayer £5.1bn every year, and that the money from the tax could better be put towards funding more school sport and expanding school breakfast clubs.