Webber decided to quit six months ago

Mark Webber has admitted he made the decision to quit formula one at least six months ago.

The Australian told his boss, Red Bull principal Christian Horner, of his decision to switch to Le Mans with Porsche next year just an hour before the announcement was made early on Thursday.

But Webber told Melbourne newspaper The Age: "It’s been on the cards for a long while, towards the back end of 2012 for myself.

"The decision was made before Christmas," he added.

"That’s why I had all you guys (reporters) out for dinner in Melbourne. I knew that was my last race in Australia."

Webber, 37 in August, therefore insisted that the ’Multi-21’ fallout with teammate Sebastian Vettel had nothing to do with his decision.

Rather, "You can’t be at this level with the motivation not at tip-top," he explained.