Sportswear giant Adidas are said to be furious that England players have been allowed to wear Nike clothing in their free time at the World Cup, despite the fact that Adidas are a title sponsor, reports the Daily Mail.
The row centres on the England players wearing Nike garments during their leisure time.
Nike are the official kit sponsor of England, and as such England players are contractually obliged to wear Nike kit on the pitch and in training. Adidas know there is little they can do about this situation.
However, off the field and in leisure time England players have been photographed wearing Nike leisure wear, that has no link to the England kit or official England merchandise, and it is this that has got rival Adidas in a fury.
According to the Daily Mail, Nike have three members of staff employed to work within the England set-up to ensure that Nike branding is heavily associated with the England team.
However, the contract to supply England should only apply to team kit, and to those individuals personally sponsored by Nike.
Adidas are personal sponsors of England players Steven Gerrard, Leighton Baines, Frank Lampard and Phil Jagielka and they are angry that even their own players are being required to wear Nike leisure wear.
It is understood that Adidas have notified the FA of their displeasure at the situation, and are said to be considering legal action.
The market for football merchandise is enormous, and the World Cup is the biggest stage for major brands including Nike, Adidas and Puma. Nike and Adidas currently enjoy a 70% combined share of the football market.
Adidas have enjoyed a longer relationship with football than Nike, who only entered the market after the USA World Cup in 1994. Adidas on the other hand have sponsored the FIFA World Cup since 1970, and have recently renewed their deal through to 2030.