Rubens Barrichello has threatened to quit Formula 1 if he finds out his Brawn team are favouring Jenson Button.
The Brazilian lost Sunday's Spanish Grand Prix to his team-mate after boss Ross Brawn changed Button's strategy.
"If I get the slightest sniff of the fact that they have favoured Jenson, I will hang up my helmet tomorrow," he told United States channel SpeedTV.
"But I know Ross wouldn't do that. He asked me to drive for him and he knows I want to race fairly with Jenson."
Team orders is a sensitive subject for the veteran Brazilian, who left Ferrari in 2005 a year before the end of his contract because he was fed up with not being allowed to race team-mate Michael Schumacher.
Brawn was Ferrari's technical director at the time.
Barrichello blames race tactics
Barrichello will also be aware that Button's win extended his lead in the world championship over his team-mate to 14 points - and that there will eventually come a time when Brawn have to focus their efforts on one driver as they seek to fend off the threat from other teams.
Asked if he feared a return to those days with his new team, Barrichello said: "I have had experience of that and if it happens I won't follow any team orders. I'm making this clear now but we have a much more friendly situation in this team.
"There's no way I'm going to be crying and saying I should have this or that. I had the ability to win and I didn't."
Barrichello had expected to win the race after making a brilliant start from third on the grid and leading into the first corner.
Brawn planned for both cars to do three pit stops but they changed Button's strategy at his first stop because they were worried he would otherwise get held up by the Williams of Nico Rosberg - who Barrichello only just emerged ahead of after his first stop.
'Slow' Barrichello disappoints Brawn
Button then proceeded to set an impressive series of times, despite his heavy fuel load early in his second stint.
However, Barrichello remained on target to win until his own second stop - he then had problems with his third set of tyres and lost sufficient time for Button to get ahead.
As the drivers waited to go out on to the podium, Barrichello sat on a sofa and asked: "How did I lose that race?"
He added: "My third set of tyres was not good, I don't know if something was broken on the car. So I couldn't keep the pace up and from then on it was a struggle to keep the car on the track and a relief to come second.
"I'm disappointed I didn't win the race because I felt I had it in the bag today but it's still great for the team."
Brawn denied there had been any decision to favour Button.
"Absolutely not," he insisted. "The strategy change was my decision. The engineers and the drivers pool their information and make their recommendations but I make the call in the pit lane and, good or bad, we stand by it.
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