The two-man crew are expected to become the first to successfully pilot a round-the-world balloon flight on Saturday.

Friday saw them cross the Atlantic and break the record for the longest balloon flight set just two weeks ago by the Cable and Wireless balloon.

Brian Smith with the latest from the control room in Geneva

Bertrand Piccard of Switzerland and Briton Brian Jones told their control room in Geneva they were "secretly confident".

But the champagne will remain on ice until the aircraft crosses the finish line.

Kevin Connolly in Geneva: "The extraordinary adventure is going to end in triumph"

"There's always a danger, and until they cross the line we won't relax," said flight engineer Alan Noble.

Meteorologists expect the balloon to cross the finish line over Mauritania - 9.27 longitude west - at around 1030 GMT on Saturday.

Mauritania, Mali and maybe Egypt await the balloon

The crew are said to be in a state of nervous exhaustion and an emotional Mr Piccard burst into tears when told that the Breitling was approaching its goal.

At 2130 GMT on Friday the balloonists were approaching the Cape Verde islands off the northwestern bulge of Africa.

The control centre said they were moving at some 110 mph after catching a jet stream over the Atlantic at an altitude of 11,000 metres (33,000 feet).

In an interview with Geneva, Mr Jones said: "We are having to work very hard and concentrate our efforts 100%."

The crew are through the worst and confident

Mr Piccard added: "There is a huge pressure here in the balloon. To relax, I've used hypnosis to sleep better."

Both said the worst moments had come on Wednesday in the stretch between Mexico and the Caribbean.

A slowing wind coincided with day-long breathing difficulties caused by a build up of carbon dioxide.

"We had a bad moment over Mexico when we were cold and tired and stressed," admitted the Swiss pilot

This cup - and $1m - awaits the crew on landing

"We took full oxygen for a few hours, slept and felt better. Now it is only a bad memory."

Pyramid dream dashed

Providing the finish line is crossed, the next decision for the team is where to land the balloon.

The pilots had hoped to land by the pyramids in Egypt. That aim has now been dashed due to high winds, but the team still hope to land in Egypt.

Virgin tycoon Richard Branson, who has made four unsuccessful attempts at the record himself, told Sky News: "They must be feeling incredibly elated and delighted at this stage."

He had been monitoring the two men's journey closely, he said, adding: "It has been a fantastic voyage and it has been wonderful in a sense to enjoy it with them."

Asked if he was disappointed that he had not broken the record, he said: "We are reasonably good at picking ourselves up and moving to other challenges.