Red Bull motorsport advisor Helmut Marko has said that Michael Schumacher needs to check his data before complaining that the world championship leaders are maintaining an unfair competitive advantage.

Earlier this month, the seven-time world champion bemoaned the fact that Red Bull Racing was continuing to flout the area of F1's Resource Restriction Agreement covering the size of its workforce, but Marko insists that he has misunderstood the state of the agreement between the teams.

"There was an agreement that everyone would have the same size, but certain teams don't respect that," Schumacher claimed, "Now there seem to be different visions. If you take the number of people we have compared with Red Bull, that is very different. Will Mercedes have to go to an open field again or will the teams respect what they agreed and do that? We are not on the same playing field."

While Red Bull Racing employees around 550 people at its Milton Keynes base, Schumacher's Mercedes operation employs close to 400 in Brackley, with another 20 or so to cover administration and marketing at its German home in Stuttgart. The Three-Pointed Star, however, produces its own engines, and this prompted Marko to reveal a different view of the situation, explaining that the number of employees was never settled upon because of concerns that Red Bull, a Renault customer, had over the wording of the clause covering the workforce.

"The agreement never came into force," the Austrian told Germany's Auto Bild magazine, "We were reluctant because [the staff limit clauses] were purely for the chassis development. Mr Schumacher should be asking how many people work on his Mercedes engine in Brixworth. Why should we make concessions in the development of the chassis when Mercedes has every freedom for the engine?"

Marko insisted that if staff numbers were also limited when it came to the engine department - where Mercedes is reckoned to employ a further 400 people - then the agreement may be negotiable. Renault uses just 170 people to run its development programme at Viry-Chatillon in France. The German manufacturer supplies engines to McLaren and Force India as well as its 'works' team, while Renault provides powerplants to its own team, Lotus Renault GP, and Team Lotus, as well as RBR - and has said that it would be open to supplying a fourth outfit, amid rumours that Williams may be looking to reunite with the regie.