Having first switched on the black kettle in the Ferrari garage, Ferrari Technical Director Ross Brown has warned Renault not to play dirty with team orders as Fernando Alonso and Michael Schuamcher prepare to go head-to-head in the World Championship.

The role of Felipe Massa and Giancarlo Fisichella, the respective number twos at Ferrari and Renault, is set to be put in the spotlight during the final two races of the season following claims that Fisi deliberately blocked Schumacher in China.

"What we mustn't have is the number two drivers blocking or intentionally slowing one of the championship contenders," declared Brawn. "It would be unfortunate and unacceptable. It is something I know we were involved in a few years ago and it was considered to be normal practice then, but it has been deemed to be unacceptable now, so we understand that.

"I think there is a certain level that is logical and fair and there is another level that has to be avoided because it is not correct."

While team orders have been officially banned, Brawn acknowledged that a driver could still strive to support his team-mate even without a specific request from his employers.

"The difficulty is after the fuss of a couple of years ago, any team orders that influence the outcome of the race are not allowed. But that doesn't stop the driver making the decision," he commented.

"If you radio your driver and say: 'Please look after the engine, please look after the tyres, we want to make sure you finish the race', everyone could interpret that as a coded message that you have to back off.

"And you make out of that what you want. It is very difficult for Felipe to win a race and stop Michael from winning the championship. I don't think he would want to do it. And the same with Giancarlo."