VALENCIA, Spain (AFP) — McLaren boss Martin Whitmarsh believes a good performance at the British Grand Prix is vital if his team are to maintain their lead in the title race.

McLaren are expecting an improvement in their form as they are set to introduce a major update package at Silverstone, which will include the exhaust-blown diffuser.

The pace-setting Red Bulls have had the exhaust-blown diffuser installed since the start of the season and Whitmarsh believes that the McLaren cars must match their speed in Silverstone if they are to compete for the world championships.

“It is an important race for us,” Whitmarsh said, “At a circuit like that we have to be competitive with Red Bull if we are going to be able to beat them this year. If we can be competitive there, we have a good chance to win both championships.

“It will be a big race, but it is not the end of it whatever happens. If we beat them they will not stand still. If they beat us we are not going to stand still. I hope it will be close and certainly closer than last year.”

Whitmarsh conceded that he arrived in Valencia feeling apprehensive as rival-teams Ferrari, Mercedes, and Renault had all brought along significant update packages which included the exhaust-blown diffuser.

In last Sunday’s race German Sebastian Vettel of Red Bull took the win ahead of championship leader Lewis Hamilton, with Jenson Button in the second McLaren in third.

But he admitted he did not feel threatened by rival teams’ improvements and believes that his team have a great chance of securing both titles.

“To come out of here leading both world championships, we’ve seen what the others have got, and to have a decent upgrade, we must believe we are in the position to have a strong second half to the season and a world championship campaign.”