Wednesday 20 May at 10:00 : May 20 (GMM) Should Sebastian Vettel continue to pull clear of his teammate and nip at the heels of the 2009 championship leader, Red Bull will put its full weight behind the 21-year-old German driver

That is the message of team boss Christian Horner, as Vettel enters this weekend's Monaco grand prix a clear favourite to battle for victory with title leader Jenson Button

After five races and a victory so far this season, Vettel is 18 points behind Brawn driver Button's lead, and 7.5 points clear of the occupant of the sister RB5, Mark Webber

"If it is clear that one of our drivers is fighting for the world championship, then we will have to concentrate on him," Horner is quoted as saying by the Austrian news agency APA

Horner, however, hastened to add that Australian Webber, 32, is "one of the most underestimated drivers" on the formula one grid

But in Germany's Sport Bild, he contrasted the pair by remarking that Vettel "drives despite his unbelievable speed very economically, using less fuel" than Webber

Horner is not sure Vettel is the favourite to win in Monaco, though

"Anything with a high-speed corner will be good for us, so I think Monaco is more Brawn-territory," the Briton acknowledged