Boots will make its revised "star-rating" licences for sun cream available to all suncare brands "shortly", after it withdrew them from competitors ahead of changing its system. The multiple made the statement following anger from competitors over the decision.

However, Boots has yet to explain how the system's standards had been changed. The multiple withdrew the licences from competitors' suncare brands, but said it had worked with Cancer Research UK to establish "more robust controls to deal with past issues of non-compliance to the star-rating system, so that customers can be sure that any brand using this system is doing so correctly".

Cancer Research UK also declined to give details, saying only that it had "exchanged letters on the matter", with Boots.

The decision to withdraw the licences provoked anger among competitors including Sainsbury's, Asda and Superdrug.

Sainsbury's said it was "disappointed" by Boots' decision to withdraw the licence from its suncare products and reassured customers that its own-brand suncreams were rated five-star.

Superdrug echoed the comments and called for an independent standard on suncare products, "not one regulated by a retailer". "Our own brand suncare continues to conform to the five-star standard, yet we can't reassure our customers by using the rating system," said Superdrug brand director Andrew Groom.