Under the mantle of the UK's Food and Drink Federation (FDF), a raft of industry food groups that include the Snack, Nut and Crisp Manufacturers Association and the British Sandwich Association have openly criticised the Welsh regulatory move as "so restrictive" that they apparently prevent healthy options.
"These new regulations are so badly drafted that they will not lead to the development of ‘healthy vending’ but will effectively mean that vending will no longer be viable in Welsh hospitals,” said Julian Hunt, FDF director of communications.
Set against the backdrop of soaring obesity figures and burdensome healthcare costs, in November last year Wales introduced a ban on the sale of junk food in hospital vending machines to improve people's diets.
But for the FDF coalition, the rules that determined which products could be sold were based on a model developed by the Food Standards Agency for use in deciding which foods can be advertised to children.
"Part of the problem stems from the fact that ministers have decided to use the FSA’s nutrient profiling model to underpin their regulations, despite the fact this particular tool was developed originally with the sole purpose of supporting Ofcom's rules on TV advertising to children," said the coalition.
The group, which also includes the welsh National Farmers’ Union Cymru, added that the FSA itself advised Welsh ministers against the use of the tool in relation to vending in hospitals, "but its advice was rejected".
The nutrient profiling model, that hones in on saturated fat, sugars and salt was developed by the UK's food agency as a tool for categorising foods on the basis of their nutrient content.
The model, a 'simple scoring' system, allocates points on the basis of the nutritional content in 100g of a food or drink. A maximum of ten points can be awarded for each nutrient.
The call for the Welsh assembly to review the rules comes after the British Sandwich Association recently criticised the guidelines, claiming that while a premium bacon, lettuce and tomato with malted wheat grain bread or a wholemeal cheese and tomato sandwich fail the rules, a standard tuna mayonnaise and sweet corn on white bread meets the requirement.
Raising awareness, last week the coalition hosted a fringe event at the Welsh Conservative party conference "to debate whether the regulations reduce choice too far".