Environmental activists are planning worldwide protests against Adidas at the weekend, calling on the sportswear giant to clean up production of its World Cup merchandise.

Greenpeace is accusing World Cup sponsor Adidas of "hiding behind empty promises," after claiming to have found high levels of hazardous chemicals in merchandise produced ahead of this year's football tournament in Brazil.

The activists also say products from Nike and Puma were among 33 items including boots, goalkeeper gloves and the official 'Brazuca' ball, that contained a range of substances uncovered by independent laboratory tests.

But Adidas and Nike have both refuted the claims, telling just-style last week that the levels identified all meet legal requirements.

Adidas, Nike and Puma have all joined Greenpeace's Detox campaign, which commits them to eliminate all hazardous chemicals from their products and supply chains by 2020. 

But the activists say the latest chemicals tests show that the promised steps are "much too timid." They intend to ramp up their campaign by protesting outside Adidas stores worldwide on Saturday (31 May), including those in Hong Kong, Taiwan, Russia, Indonesia, the Philippines and Mexico.