Lewis Hamilton was at the famous Claridge's Hotel in London on Thursday proving why he is worth his weight in gold to the sponsors, who could make him the richest sportsman on earth.

Hamilton, 23, was on time to endorse Vodafone's latest product.

He was on public show less than a week after he won his first world championship in front of a television audience that peaked at more than 13 million.

As the credit crunch was shredding bank accounts across the globe, Formula One rolled seamlessly on to its spectacular conclusion at the Brazilian Grand Prix last Sunday.

The £100 million (S$236 million) champion drove a £1 million car, for a team that spent more than £200 million to win the title, before jetting home in a £25 million private aircraft.

No wonder viewers are awestruck and sponsors adore Formula One. This is sport in the fast lane. But for how much longer?

Even Formula One's executives are starting to worry that the money is going to run out.

Meetings have been taking place all week among team principals and officials from the FIA, the world governing body, to find ways of reducing the extraordinary cost of running a Formula One team.

Gerhard Berger, the principal of Toro Rosso, one of the smallest teams, is under no illusion.

'It is going to be difficult. If you look at big sponsors coming into Formula One, it is very seldom,' he said.

While the world tightens its collective belt, Formula One is fuelled by such huge amounts that even football looks poverty-stricken.

Vodafone, the world's biggest telecommunications company, pulled the plug on its four-year shirt sponsorship deal with English football club Manchester United in 2005 and is ending its sponsorship of the Champions League.

Even then, the estimated £30 million a year that Vodafone spends on McLaren is almost twice as much as it spent on United (£9 million a year) and the Champions League (£8 million) combined.

But the question is whether the telecom businesses, the banks and the insurance companies - Formula One's biggest sponsors - can continue to spend big.

They see Formula One as the ultimate advertising vehicle because it attracts hundreds of millions of viewers, who are tantalised by the sight of the world's fastest cars driven by daring young men, surrounded by beautiful young women.

Countries are keen to host a Grand Prix because governments reportedly earn up to five times their investment in tourism and advertising.

Abu Dhabi has been added to the calendar and South Korea, Russia and India are anxious to be involved.

But all that depends on there being enough fans with money to travel to each new and exotic location and sponsors who can afford to fill private planes to fly their guests to five-star hotels to quaff champagne and admire Hamilton drive.

Those involved with Formula One, the richest and most expensive sport on earth, are anxiously watching whether the credit crunch turns out to be the biggest collision in its 58-year history.

THE TIMES, LONDON