Hakkinen remains on Williams list

The Finn was courted by the team earlier this year and was eager to get back behind the wheel of a Formula 1 cockpit, but the deal fell apart when Williams was approached by Button's management and opted to ink a deal with the Briton instead.

However, after F1's Contracts Recognition Board ruled that Button was not free to sign for Williams because his contract with BAR was valid, Williams is now believed to be considering its original favoured option.

Speaking to Autosport this week, Williams co-owner Patrick Head said: "It would be a risk after he has been out of the sport for three seasons, but you have to think seriously about a man who has the talent to twice beat Michael Schumacher to the title."

Williams is eager to get a driver with a proven record to join Webber next season because the Australian does not have the kind of results that would justify putting him as a number one at a team gunning for the world championship.

"While I'm sure that Mark will go on to be a successful grand prix driver, it's a fact that his best result to date is a fifth-place finish with Minardi. We have to question if it would be correct for a leading team such as Williams to partner him with another driver lacking in hard results."

Despite the Hakkinen speculation, test driver Antonio Pizzonia remains favourite to land the second seat at Williams, with David Coulthard, Anthony Davidson and Nick Heidfeld also believed to be strong contenders.