Red Bull Formula One driver Mark Webber of Australia drives during the second practice session of the Malaysian F1 Grand Prix at Sepang International Circuit outside Kuala Lumpur March 23, 2012. REUTERS/Edgar Su (MALAYSIA - Tags: SPORT MOTORSPORT)

Formula One World champions Red Bull must modify the floor of their cars for next week's Canadian Grand Prix after the sport's governing body issued a formal clarification of the rules.

A spokesman for the governing International Automobile Federation said race director and technical head Charlie Whiting had sent all teams a directive on Friday following allegations that the Red Bull floor had an illegal hole.

The argument in question is arcane even by Formula One standards, with technical experts arguing over 'fully enclosed holes', the difference between a 'hole' and a 'slot' and even what constitutes a hole.

Such holes can produce aerodynamic benefits and, in his note, Whiting set out what was permissible.

The directive reads:

“Following on from a number of discussions in Monaco, during which it became clear that certain misunderstandings existed, we feel it would be helpful to make our position clear.

The controversy erupted hours before last month's Monaco Grand Prix, with Mark Webber starting on pole position for Red Bull.

Rivals had appeared set to protest the Red Bull's floor, which they argued had an illegal “fully enclosed hole” on the surface of the step plane of the floor.

In the end, there was no protest and Webber celebrated his first win of the season - and Red Bull's second - but the FIA was aware of the situation and acted anyway.


“It has been argued that, as it is not explicitly stated that fully enclosed holes cannot be located in a surface lying on the step plane rearward of a line 450mm forward of the rear face of the cockpit template, then they may be located in such areas,” declared the FIA directive.

“We disagree with this view and consider it implicit that fully enclosed holes may not be located there.

“If they were permitted the opening part of the second paragraph of Article 3.12.5 (which was added to the regulations at the same time as Articles 3.12.9 and 3.12.10 for 2011) would be superfluous.”

Red Bull, who are leading McLaren in the constructors' standings by 38 points after six of 20 races, have been adamant that their floor was legal and rebuffed doubts in Monaco.

Team principal Christian Horner said at the time: “There was a bit of a fuss after the Bahrain race (won by Red Bull's Sebastian Vettel in April) but it was clear the car complied. We sought clarification after that, but there is no doubt the car is fully compliant.” - Reuters