Fernando Alonso and McLaren surprised Formula One yesterday by announcing that the Spanish world champion will leave Renault to join forces with Ron Dennis's team in 2007.
The 24-year-old Spaniard became the sport's youngest champion in September, winning seven grands prix to beat McLaren's Kimi Raikkonen by 21 points, and last April extended his contract with Renault to the end of 2006. Alonso also helped the Oxfordshire-based team to the constructors' title ahead of McLaren.
Alonso's arrival would appear to clear the way for Raikkonen to leave for Ferrari. Raikkonen is out of contract at the end of 2006 and has long been coveted by Ferrari as a replacement for the seven-times world champion Michael Schumacher, who is expected to retire at the end of 2007.
There will also be the question of who replaces Alonso at Renault. The Australian Mark Webber will be out of contract with Williams by 2007, while Renault also have the promising Finn Heikki Kovalainen waiting in the wings.
The decision of Alonso, who wants to deliver another world championship to Renault as a parting gift after sealing his "dream" move to McLaren, raises questions over Renault's long-term commitment to Formula One.
Despite his attachment to Renault, Alonso revealed he had little hesitation in accepting McLaren's offer.
"I achieved my lifetime ambition with Renault this year and I felt that it was time for a new challenge," he said. "To become part of a team with such a desire to succeed and passion for performance is a dream come true for any driver. It will be a new beginning for me.
"I'm pleased that we are able to make this announcement now as it will allow my team and I to focus 100 per cent on defending the world championship next year."
Alonso continued: "I am concentrating on 2006. Renault brought me into Formula One, brought me my first title, and I will be working to repeat that success next year.
"I will be sad to leave Renault, but sometimes possibilities come along which are just too good to miss."
Alonso's manager, Flavio Briatore, also runs the Renault team, so the defection of their leading driver is unlikely to have come as a shock to him.
Renault's president, Patrick Faure, said: "I was disappointed to learn of Fernando's decision but by the end of 2006 he will have spent five seasons with us. Fresh challenges are essential for any sportsman, and he has taken the decision to pursue a new direction. That is part of Formula One, and part of life."
However, the driver's departure will raise further questions about Renault's long-term commitment to Formula One. They have stated that they will stay in the sport for as long as there are clear benefits.
For McLaren, the capture of Alonso comes on the back of a sponsorship deal with Vodafone and signals their desire to win a world title for the first time since Mika Hakkinen in 1999.
Team principal Ron Dennis said: "We always make it clear that we want to be the best and the only way of achieving this objective is by attracting the best people, the best drivers and the best sponsors."
He added: "Both Juan Pablo [Montoya] and Kimi [Raikkonen] are extremely talented, professional and competitive Formula One drivers and they have and will continue to concentrate on our joint challenge for the championships.
"Our aim for next year remains absolutely clear to everybody within the team we want to win races and be in a position where we might have two Formula One world champions driving for McLaren in 2007."
McLaren's kings of speed
* AYRTON SENNA 1988-1993
Arguably the greatest driver of all. In Ron Dennis he found a boss who shared his insatiable appetite for victory. Won three championships in four seasons.
* ALAIN PROST 1980, 1984-89
Like Alonso, Prost made his name at Renault before his move to McLaren. Won three consecutive championships before Senna's arrival heralded bitter battle for driver supremacy.
* EMERSON FITTIPALDI 1974-75
Won second world title as part or the McLaren super-team of the mid-1970s. Was Brazil's first Formula One success story.