But it looks a long shot at best. At worst, his decision to change teams could mark the beginning of the end of his career.

Button is a fairly sensible individual. Yet somewhere along the line his head has been turned and McLaren have taken advantage. They will not expect him to trouble Hamilton, but his signing at McLaren makes a mess of Ross Brawn's plans. It "gets him back" for luring Mercedes-Benz away from McLaren, and it gives McLaren a good-news story with their all-English "dream team".

While McLaren were talking up their new signing, there was dismay at the Brawn GP team, who made Button's maiden world championship possible.

There is no doubt that some at their Northamptonshire HQ believe he has kicked sand in their faces in return for their efforts and there is anger at the way he has walked out, largely over money.

It may be that these feelings run strongest towards Button's management team rather than the driver, but the most controversial deal involving British drivers in F1 for many years has left a trail of bad blood.

There are always pros and cons for any sportsman when it comes to moving teams, but the landscape in this case looks tilted against Button. Perhaps the many paddock judges who have underestimated him are wrong and he will show us, once and for all, just how good he really is when matched with Hamilton.

The upside for Button, 29, is that he gets to drive for one of the great teams for the first time. If not Ferrari, then McLaren.

Button will probably have a good car under him in next season's MP4/25 and he will have been assured that he will get equal treatment with Hamilton.

McLaren can build good cars, they know how to develop them and their engineers and designers are among the best. So Button has every chance of defending his title next year or perhaps reclaiming it in 2011.

On the cost side, Button has walked out of a team run by the undisputed pit-lane king, Brawn; he has thrown away all of the benefits of continuity that his long stint at Honda and Brawn has brought him; he has left a team that have just been taken over by Mercedes, the last of the great manufacturers still in the sport and who should have another decent car on the grid for next year.

What is more, Button could have expected to lead from the front.

As for his prospects at McLaren, he will now take on one of the most entrenched drivers in a team in recent history in Hamilton.

Button will have to fight with every fibre at every test, practice session, qualifying session and race not to be next on Hamilton's chopping block.

And then there is Hamilton himself. The 2008 world champion has to win. It is the only option.

Already regarded as likely to be one of the greats, the 24-year-old enhanced his reputation this year by showing he can wrench a bad car up the grid. - ©The Times, London