Jenson Button has been warned he should not assume he will win the world championship this season, even if the Briton romps to a fifth victory in six races in Monaco.

Red Bull boss Christian Horner knows the tight, twisting Monte Carlo street circuit will suit Button's Brawn GP car better than the one driven by his own man, Sebastian Vettel.

But Horner insisted Vettel can strike back when the title chase heads to faster tracks over the summer.

Button's dominance of the championship sees him go to his 'home' Grand Prix - he lives in the principality - with 41 points. Brazilian team-mate Rubens Barrichello is 14 points in arrears while Vettel, the young German who won in China and finished fourth behind the other Red Bull of Mark Webber last time out in Spain, trails Button by 18 points.

The daunting gap is likely to grow wider on Sunday, yet a defiant Horner said: "We still absolutely feel we're in this championship. The performance of the car in Spain was again positive, and both drivers have demonstrated the potential of it.

"We've not had the rub of the green in the last couple of races, and Brawn have taken advantage of that. But it's a long season, and we've some tracks coming up that will really suit the characteristics of our car.

"Anything with a high-speed corner will be good for us, so Monaco is more Brawn territory.

"But there's no reason why we shouldn't be in good shape at all tracks, in particular at Turkey and Silverstone as they will suit the characteristics of our car."

There is the prospect the Red Bulls will have on board around Monte Carlo a new rear diffuser which was the cause of so much controversy at the start of the season. Horner added: "Our guys in Milton Keynes have been working very hard on it. Every team that has so far put one far has found some performance."

Meanwhile, Ferrari were set to learn later today whether they have won an injunction to prevent the FIA bringing in a £40million budget cap on teams next season.

The sport's most successful team have threatened to quit Formula One if the rules are not re-written. Renault, Toyota and Red Bull's two teams have taken a similar stance.