Teams have agreed to ban the controversial F-duct device - pioneered by McLaren - from next season.

Since McLaren first introduced the device at the season opening Bahrain Grand Prix, a number of teams have copied it with varying degrees of success.

Like most great ideas it is relatively simple. The driver controls a vent in the cockpit through which air is channelled to the rear wing. By opening the vent, thereby increasing the flow of air, the rear wing effectively 'stalls', lessening downforce and increasing top speed. While only used on the straights it has shown itself, particularly on the McLaren - where the vent is controlled by the driver's left knee - to be very effective.

While some teams have been unhappy with the device ever since it was introduced, claiming that it flouts the rule that bans movable aerodynamic devices, the FIA gave it the thumbs up.

This weekend however, there has been added concern in terms of safety, with Fernando Alonso seen at times to have only one thumb on the steering wheel of his car as he uses the back of his right hand to control the F-duct's air flow and his right is off the wheel controlling his car's brake balance.

While McLaren called on its rival teams not to ban the device, it is believed that the growing concern over safety was the deciding factor.

"It's a clever piece of engineering and hats off to the guys who invented it," said Red Bull's Christian Horner, according to the BBC, "but some of the solutions this weekend look a little bit marginal when you see drivers driving with no hands basically. So I think there is a safety issue and a cost issue to take into account."

When asked about the device earlier this weekend, and the fact that at times he didn't appear to have his hands on the steering wheel, Alonso told reporters: "I always have my hands on the wheel. All the drivers operate the brake balance these days, and the button for changing the front wing and there are other buttons as well. I think there is nothing wrong with that."