The FIA is to defer the introduction of a new rule regarding engine mapping until after next weekend's Monaco Grand Prix.

Earlier this week, the sport's governing body wrote to the teams announcing that it intended introducing a rule banning them from of using their engine management systems to gain an aerodynamic advantage with immediate effect. However, it subsequently announced that the rule would not be introduced until after this weekend's race in Spain.

Talking to reporters in Barcelona this morning, Virgin team boss John Booth revealed that the FIA will now wait until after Monaco.

"I think Charlie Whiting classed it as moveable aerodynamics and he's possibly right," he said. "A ban on it would have affected us less than the leading teams because we are quite a long way behind on the engine mapping side. Now it has been postponed for two races, which is a little bit disappointing."

Although most of the teams have adopted the ploy, it is widely thought the introduction of the rule is to prevent Red Bull running away with both titles. Indeed, Mark Webber virtually said as much yesterday when he commented that the rules change "every hour".

"At the start of the week it was banned, this week not, today not," said the Australian. "There's another Technical Working Group meeting after Monaco but I think it will affect all the top teams that have utilising this system, not just this year but obviously a little bit last year."