Mark Webber's turbulent month with Red Bull took another twist on Saturday as he was relegated to the back of the grid for the Chinese Grand Prix after suffering a fuel problem in qualifying.
The Australian, who has been in the spotlight after team-mate Sebastian Vettel defied orders to snatch victory from him last month in Malaysia, ground to a halt in the second session of qualifying in Shanghai.
Race stewards penalised Webber for not having enough fuel in his car for a sample and because he could not drive the car back to the pits. He had set only the 14th-fastest time, but that was declared void.
Red Bull blamed an error with a fuel browser for putting insufficient fuel in the car.
"It's very disappointing," said Webber.
"Q1 (the first of three qualifying sessions) went okay; I was comfortable with the car and we had a good plan for the rest of the session.
"In Q2 we lost fuel pressure so I had to turn the car off and couldn't get it back to the pits.
"I had to stop on the circuit, so qualifying was over before it started really. We need a bit of luck now; it's not the optimum starting position, but we still have to try to get something from there."
Race stewards said in a statement: "The team admitted it had not put sufficient fuel in the car... only 150ml of fuel was on board, which was insufficient to provide the one-litre fuel sample and drive the car back to the pits under its own power."