The BBC's John Young: Team prepared for the worst

The Virgin tycoon and his two co-pilots have just a few hours in which to find an easterly wind to carry them towards the west coast of America or face having to ditch their balloon in the Pacific Ocean.

Project director Mike Kendrick said it now looks as if the crew have a less than 50-50 chance of continuing the flight.

"It is not looking good at the moment, I must admit," he said.

The 272-foot-high balloon is stuck in a weather system known as a trough, 200 miles off the coast of Hawaii and is being pushed south instead of east.

Crew are determined to fight to the end

Mr Kendrick said: "We were always worried about this trough and we did get stuck in it overnight."

The crew have set themselves a deadline of daybreak (1800 GMT) to find a strong enough easterly wind to take them out of the trough.

Mr Kendrick added: "When the sun comes up and warms the balloon it floats up to a natural altitude of 30,000 feet, and once its there it will be carried by whatever wind there is around."

But if the crew wait until that point, the danger is that the balloon could be blown back out into the Pacific, out of reach of rescue teams in Hawaii.

The ICO Global balloon is presently hovering north-northwest of Hawaii, 2,800 miles from the US mainland.

Mr Branson and his co-pilots Per Lindstrand and Steve Fossett have been manoeuvring the balloon to different heights, going down as low as 6,000ft in their frantic search to find a wind that will take them to the US.

Kendrick: Crew fell down a 'plughole' in the sky

Mr Kendrick said: "They are fighting very hard and while we have the duration, they won't be prepared to give up.

"You wouldn't expect those three to do anything else."

The three had picked up a small easterly wind. But this was only carrying the crew at about 14 knots, which was not strong enough to carry the balloon out of trouble.

Mr Kendrick said: "This is a real piece of weather that catches balloons out all the time.

"There is nothing we could have done about it at all."

But he added that the record breaking bid was far from over and the three balloonists were determined to fight to the end.

"We want to stay here. We want to fight this, we want to win this back," said Mr Kendrick.

The latest setback comes after the balloon reached the half-way stage on Thursday, approximately 1,700 miles from the coast of Japan.

The crew had been hoping to reach the west coast of America before dawn, just in time for Christmas.

Balloon a long way from the Moroccan launch site

If the team were to make America's west coast they would break the balloon distance record set by American millionaire Steve Fossett set on a previous attempt to circumnavigate the globe earlier this year.

But it was the hazardous Pacific which scuppered Fossett's venture, forcing him to ditch hundreds of miles from the coast in shark-infested waters.

The three-man crew of the ICO Global, all veteran balloonists, have already experienced more than their fair share of dramas since taking off on their 24,000-mile journey.

Tense negotiations this week with the Chinese authorities, which were trying to prevent the balloon from entering the country's airspace, have culminated in Beijing telling other balloon challengers to hold off their attempts.

Rival balloon team Breitling Orbiter III said the Chinese embassy had sent a fax on Wednesday saying that, for an indefinite period, no other balloons would be permitted to enter Chinese airspace.

The Breitling Orbiter team hit back at the ICO Global attempt, saying: "Branson's strongarm tactics are hamstringing the departure of other competitors."