Ahead of the FIFA World Cup football tournament that kicks off later this week, major sponsors Adidas and Nike are accused of paying poverty wages to supply chain workers who make the football shirts and boots worn by players and supporters.

Between them, the two sportswear giants sponsor 22 out of the 32 teams, with the Nike kit deal for the French national team worth EUR50.5m a year and Adidas sponsoring the German team to the tune of EUR65m per year.

But according to a new 'Foul Play' report from the Clean Clothes Campaign (CCC) and Éthiquesur l'étiquett, these multimillion pound sponsorship deals are out of kilter with supply chain workers' wages.

Indeed, an analysis of the current production costs of Nike and Adidas sport shoes with those of 25 years ago shows the share of these costs that ends up in a workers' pocket is now 30% less than in the early 1990s.

Much of the brands' sportswear is produced in Indonesia, where 80% of garment workers are women and earn between EUR82 and EUR200 per month, according to the report.

It adds that these wages often do not even cover basic needs, and is much less than the EUR363 that the Asia Floor Wage calculates would enable them and their families to have decent lives.

Unions and worker rights groups are now calling on Adidas and Nike to ensure living wages throughout their supply chain.

They calculate that if Nike and Adidas had kept their sponsor contracts at 2012 levels, they would have saved enough money to cover living wages for the workers in their main production countries China, Vietnam, Indonesia and Cambodia for one year.

A spokesperson for Adidas told just-style that "adherence to fair and safe working conditions and fair wages in factories throughout the supply chain are an integral part of Adidas' business policy and part of the contractual agreements with our suppliers."

While the German sportswear company does not determine the wages suppliers pay their employees, "Adidas requires employers to pay at least the remuneration required by law or negotiated in a collective bargaining process.

"In addition to the general economic conditions and cost of living of a country, however, national laws, the number and availability of the workforce in the country, the skills and competences of an employee, the nature of the sector or industry and the competitiveness of the employer also influence the determination of wages."

The company adds: "The average monthly take-home wage of production workers in the facilities Adidas works with in Indonesia is currently well above the current minimum wage. Take-home wage consists of the monthly wage plus benefits (e.g. performance bonus, meal allowance, living allowance, seniority bonus)."

As yet, there has been no response from Nike.