As the UEFA European championship 2016 nears its climax in Paris at the weekend, the three main sportswear sponsors have been criticised for shifting their supply chains around countries in Asia where workers who make their shirts earn less than the living wage.

Nike, Adidas and Puma invest massively in endorsement deals with players, national teams and clubs, according to a report by Collectif Ethique sur l'étiquette (Clean Clothes Campaign in France), yet fail to address the adverse impact this had on wages and labour regulation.

The report 'Foul Play' says European football endorsements have reached "astronomical levels," with deals made with the ten biggest teams soaring from EUR262m to more than EUR405m (US$449m) since 2013.

To increase profit margins the brands have to sell more products to more consumers – which in turn requires large investments in innovation and an ever-increasing media presence.

The report notes that the big sportswear brands consequently operate a tight system of cost control, setting the desired retail price and profit margin for each shoe model, and from there calculating the maximum production cost for the item.

"They then sit down with their suppliers to determine which raw materials to use, their origin and price, as well as the exact number of minutes allotted to manufacturing and how much workers are to be paid.

"This leads to situations as the production of the German football team shirts, which is sold for EUR85: 60 cents goes to the garment worker, while a profit of EUR24.3 goes to Adidas."

Describing this as "a bad business model for workers," researchers add that wages are too low to meet basic needs.

They also point out that sportswear brands are massively shifting their sourcing from China, where wages have seen significant increases, to Vietnam, Indonesia, and soon also to Myanmar, India and Pakistan, where lower wages allow for significant labour cost savings.

"In this way, they expose themselves to significant breaches in labour standards (unpaid overtime, no paid vacation, discrimination and impediments to organised labour)," the report says, adding: "They try to curb these issues through an increasingly sophisticated and costly system of labour audits which however does little to address the main problems."

The Clean Clothes Campaign argues that paying a living wage would represent only a few dozen cents more in the final price tag of a pair of sneakers or a sports jersey.

And it calculates the endorsement costs of the ten largest European football clubs since 2013 would have been sufficient to pay living wages to 165,000 workers in Vietnam and 110,000 workers in Indonesia.

The labour rights group urges transnational companies to be responsible for their full supply chain and to adopt purchasing practices that allow a living wage for workers.

They also stress the importance of legally binding regulation, such as the bill being discussed by the French Parliament that would require transnational companies to develop due diligence plans for their full supply chains.