F1: Red Bull question legality of Mercedes' sidepod-less W13

Mercedes turned heads in Bahrain on Thursday when they unveiled the aggressive new design of their W13 ahead of the new season. The Silver Arrows car has "disappearing sidepods" owing to an innovative cooling system design and it has been the talk of the official pre-season test in the desert.

As soon as the Mercedes left the garage on its first outing, Red Bull Racing chief Christian Horner started questioning its legality. The British team principal feels the Brackley-based team are "violating the spirit of the rules" with their new sidepod-less W13.

Ahead of the pre-season test, there were numerous rumours about Mercedes arriving in Bahrain with a whole new design. And it proved to be true as the Silver Arrows challenger was wheeled out for a photo shoot prior to the start of Day 1 of the three-day pre-season test.

Horner has made it very clear that Red Bull are not happy with Mercedes' new design. The Austrian team's technical director and aerodynamics legend Adrian Newey is said to be very keenly casting an eye over the reigning constructors' champions' new car with a view to a potential full scale protest in the near future.

"The new Mercedes violates the spirit of the regulations," Red Bull boss Horner said, as quoted by Planet F1. "For us, there are some parts that are not legal."

Ross Brawn, the Managing Director, Motor Sports and technical director for the Formula One Group, was asked about Mercedes not keeping to the "spirit of the regulations" during an interview in the pitlane.

The former Ferrari technical director admitted that it was a very innovative design, but made it clear that the "wording" of the new rules could be changed with immediate effect if a team is not keeping to the objective of the new regulations.