Team sources said some had hedged their bets by routing personnel on return flights via Abu Dhabi, Dubai or Oman with alternative reservations for the last leg of the journey back from Shanghai.

That would allow them to bypass Bahrain if the race was canceled.

A report in the Times newspaper that some teams had given "hundreds of engineers, mechanics and catering staff" two sets of tickets — one a simple return to China and the other back via Bahrain — was seen as wide of the mark by some.

"Maybe some teams can afford that but it's not something we are doing," said a member of one of the less wealthy teams while waiting at London's Heathrow airport for a flight.

"That would cost an arm and a leg. We definitely don't have that sort of cash." The governing International Automobile Federation (FIA), commercial supremo Bernie Ecclestone and Bahrain organizers have all said the April 22 race is on.

Top British-based teams have also been supportive, in public at least and despite evident doubts.

"I feel very uncomfortable about going to Bahrain," one unnamed principal told the Guardian newspaper yesterday.

An FIA spokesman said over the weekend that the Paris-based body was "constantly monitoring and evaluating the situation" and keeping in touch daily with foreign embassies and the authorities in Bahrain.

A McLaren spokesman, whose team is part-owned by Bahrain's Mumtalakat sovereign wealth fund, said any decisions were up to the governing body.

"It is the FIA Formula One world championship and we look to the FIA to offer us guidance," he said.

FIA president Jean Todt is expected to be in China, as is Ecclestone, and there are likely to be a number of meetings in the Shanghai paddock — possibly up until as late as Sunday morning.

Last year's Bahrain Grand Prix was repeatedly re-scheduled and then reluctantly canceled by organizers. Circuit chairman Zayed Alzayani said last month that the race contributes $220 million directly to the local economy and $400-500 million indirectly.