Hispania boss Colin Kolles has threatened to protest rival teams that use hot-blown diffusers in Monaco next week.

Speaking at a press conference on Friday, Charlie Whiting warned that such a move was possible following the FIA's U-turn on an immediate ban on the devices. Speaking to the assembled media, when asked if a ban was possible, he replied: "It's always a possibility, and I've made that clear to the teams that it could happen.

"We would take it to the stewards in the normal way," he continued. "We always maintain, in all of our technical directives that we have sent for many years now, that this is merely the opinion of a technical department, and anyone is free to challenge it in front of the stewards. It doesn't happen very often, but has happened in the past.

"I'd like to think that probably wouldn't happen," he added, "but one never knows. It's not beyond the realms of possibility. A protest is open to anybody. It would go before the stewards."

Sure enough, speaking in Barcelona, as the F1 circus prepares to head to Monaco, Kolles admitted to the BBC that he is considering such a move if the FIA doesn't enforce a ban with immediate effect.

"It is clear that the other cars are illegal and it brings the teams a huge advantage," he said. "This is illegal. You cannot influence the aerodynamics by hot exhaust gasses or any moveable devices. We have studied this very carefully. The point is it is not corresponding to the regulations. It brings the other teams a huge advantage. If this is not going to be stopped before Monaco we have no other choice than to make a protest.

"I cannot tell you at what stage during the Monaco Grand Prix we would protest," he added. "The only reason why we are not considering it [now] is because we were not involved in any sporting decision today."