The Lotus team has filed a protest against Mercedes's rear wing ahead of this weekend's Chinese Grand Prix.
Although the FIA had deemed the DRS wing legal twice in the previous two races, Lotus has decided to officially protest its legality ahead of the Shanghai race, the third round of the championship.
The team lodged the protest under article 3.15 of the technical regulations.
"With the exception of the parts necessary for the adjustment described in Article 3.18, any car system, device or procedure which uses driver movement as a means of altering the aerodynamic characteristics of the car is prohibited," the rules sate.
A meeting with Lotus and Mercedes representatives will be held in the afternoon in China, with the former having already lodged a 2,000 Euro deposit for the protest.
Mercedes's design helps stall the front and rear wings for a straight-line speed boost, something rival teams believe it is illegal as it makes use of driver movement when he activates the DRS.