Alonso finalises switch to McLaren

Sources close to the Woking-based outfit have revealed that Alonso has now finalised a big-money move from Ferrari to McLaren next year, renewing a partnership that ended prematurely in 2007 after a tumultuous campaign.

His decision to accept McLaren's overtures has, however, forced the team into making a difficult decision between Jenson Button and Kevin Magnussen for the seat alongside him.

The closeness of their performances this year has left the team unable to come to a swift conclusion about who should line up alongside Alonso.

For while Magnussen has impressed with his pace this season, it is Button's higher scoring rate and experience, which would help development of the new Honda engine, that has left some senior figures believing it should go with him.

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It is suggested that Alonso would prefer for Button to remain on board next year because it would help accelerate the team's push towards the front of the grid.

However, financial factors could also play a role in the decision, with Magnussen being a much cheaper option for the team.

Button did his chances of earning a new contract no harm in the Brazilian Grand Prix, coming home fourth behind the two Mercedes drivers and Felipe Massa's Williams.

It is understood that meetings will take place at Woking this week to finally settle whether it is Button or Magnussen who stays on board in 2015.

Button said at the weekend he is keeping focused on his driving, hoping it is enough to win over McLaren's bosses.

"I'm here to race [and] do the best job I can which is what I try and do every weekend," he said.

"Sometimes it doesn't work out but most of the time it does.

"All you've got to do is drive the car as fast as you can and carry yourself as well as you can. The rest isn't in your hands."

Confirmation of Alonso's 2015 plans will clear the way for Ferrari to finally go public that his replacement next year will be Sebastian Vettel.

As part of its settlement with Alonso to end his contract early, Ferrari agreed that it would not announce its 2015 line-up until the Spaniard had settled his future.

However, Red Bull's decision to go public at the Japanese Grand Prix that Vettel was leaving for Ferrari has meant his switch to Maranello became an open secret.