Sue Davies, Chief Policy Adviser for Which?, looks at the welcome turnaround in UK supermarket attitudes to food labelling.
Tesco recently announced that it will be using traffic light labelling on the front of its food labels to show the levels of fat, saturated fat, sugar and salt.
It is hard to explain the significance of this announcement. Its impact immediately became clear when Aldi and Lidl quickly followed, announcing that they too have become traffic light converts.
Which? has campaigned for traffic lights on front of pack for several years. The UK has the worst rate of obesity in Europe.
Nutrition information has been on the back of pack on most products for years, but our research testing different approaches showed that putting it on the front, with traffic light colour coding, makes it easier to tell at a glance what you are eating.
Several retailers committed early on to the scheme: Sainsbury's, Marks & Spencer, the Cooperative, Waitrose and Asda. Tesco even said it would use them at one point and then changed to a percentage guideline daily amount (GDA) label instead.
This decision had a huge influence on the main food manufacturers who, with the notable exception of McCain, proceeded to fight off any attempt to legislate for traffic lights.
But suddenly everything is different. There's only two supermarkets left: Morrison’s and Iceland.
It's hard to see how food manufacturers can continue to hide the content of their foods behind %GDAs now that supermarkets are so widely embracing traffic lights on their own-label products that sit next to them.
It will be fascinating to see which one is the first to crumble and finally do the right thing for consumers.