The FIA has decided to ban all radio transmissions that help with car or driver performances at Formula One grands prix.

F1 race director Charlie Whiting has sent a letter to all teams to say that messages from drivers asking for advice, or from teams informing their drivers about the best options to make gains on the track, would no longer be tolerated.

Whiting's directive states that "in order to ensure the requirements of Article 20.1 of the F1 sporting regulations are respected at all times, the FIA intends to rigorously enforce this regulation with immediate effect."

The ban does not target advice given on pit-stop strategies or safety issues.