There is no number one and number two driver situation at Red Bull Racing and nor will there be, regardless of the championship position - that is the insistence of the energy drinks-backed outfit's team principal Christian Horner as the 2009 F1 World Championship campaign heads towards its second half.

Whilst there have been accusations that Brawn GP is favouring title favourite Jenson Button over team-mate Rubens Barrichello - particularly in the light of the Brazilian's dubious strategy in the Spanish Grand Prix in Barcelona that arguably cost him victory, and the fact that any time anything seems to go wrong on one of the two cars, it is invariably not Button's - Red Bull is continuing to let its drivers race freely.

Some had suggested that the team may choose to switch the positions around when Mark Webber and Sebastian Vettel were running second and third respectively in the closing stages of the Turkish Grand Prix in Istanbul last month given the German's better championship standing, but no switch came - ostensibly to the frustration of the top flight's youngest-ever winner.

Though Vettel has triumphed twice now from the opening eight races of the season - in China and Britain a week-and-a-half ago - and Webber remains in search of his breakthrough victory, there are only 3.5 points between them in the chase for the crown, despite the Heppenheim native regularly seeming to have the upper hand pace-wise over his Australian colleague.

Horner, though - who has again sought to downplay any speculation of growing tension between the pair as they grapple for superiority at the Milton Keynes-based squad - is adamant that neither of them will be receiving preferential treatment or equipment between now and the finale in Abu Dhabi in four months' time.

"There's no number one driver," the Englishman told the AAP news agency. "Updates are being introduced to the cars equally at every race, and that's the way it will continue for the rest of the season.

"They're both professional drivers, they're both at different stages in their career, but they work for a strong team. Obviously there is a competitive rivalry, but it's a professional rivalry between the two of them."