Mark Webber decided to leave Formula 1 "a while" ago

Red Bull driver Mark Webber has admitted that his decision to leave Formula 1 at the end of the current season was made "quite a while" ago.

Webber will move to race sports cars with Porsche in 2014, but said that he is looking forward to the upcoming British Grand Prix.

"It is not big news to me as I have known for quite a while, but it is big news today," he told Sky Sports News. "So yeah it's exciting, but I am also looking forward to this weekend.

"We have had a decent plan in place. So now I'm just looking forward to the British GP - it has always been a decent event for me so I'm focusing on that now."

Webber has been with Red Bull since 2007.