McLaren test driver Pedro de la Rosa insists that the British Grand Prix has given a clear signal that Red Bull Racing can be beaten in the race for the 2011 F1 titles, despite the fact that the Milton Keynes-based outfit retains a handy lead in both championships.

Red Bull went into the Silverstone race being viewed as favourites to take a seventh win of the season only for Fernando Alonso to take victory for Ferrari after taking full advantage of a delay for Sebastian Vettel in the pits.

Although his McLaren team-mates Lewis Hamilton and Jenson Button endured a tough weekend on home soil, de la Rosa said that Alonso's victory and the actions of Red Bull during the latter stages of the race suggested that the title race was still open and it was 'difficult but possible' that the defending champions could be beaten.

"We have reasons to celebrate because the two Red Bulls were not only beaten, they were also overwhelmed in this GP by Fernando's race pace, which was infinitely superior to any of his rivals," the Spaniard wrote in a column for "Perhaps this has been the most convincing victory of the whole season, on a circuit which appeared to have been designed for the Red Bulls.

"The mistake with Vettel's pit stop and Red Bull's need to issue team orders to protect their number one, invites us to think that the comeback is now not a miracle, it is a possible reality, difficult but possible."

De la Rosa added that he was surprised by Red Bull's decision to bring team orders into play so early in the season, with Silverstone marking the mid-way point of the 2011 campaign.

"I cannot deny my surprise that in just the ninth race of the season team orders have been issued by Red Bull, the team comfortably leading the Championship which has always boasted of letting their drivers fight to the finish, as they did last year when Webber led the world championship and Vettel took points off him right until the end," he said. "I don't have anything against team orders. It seems right to me that they have been legalised since all drivers at some time or another have received, accepted and executed them in a more or less discreet manner. But in the ninth race, when your driver has almost double the points of the second-placed driver and your other driver had also won pole...

"Obviously everyone can do what they want and they can manage their team in the way they believe could be most profitable at the end of the season. It simply surprises me that Red Bull has put this strategic card down on the table so cheekily and so early."