Murray to miss Brazilian Grand Prix

The 77-year-old, who has developed a massive fan base during his 51 years as a commentator, will miss the race at Interlagos as he winds down his F1 commitments before retiring at the end of the season. He will not attend the Interlagos race and is also thought likely to skip the German and European Grands Prix.

"My love for the sport and my privileged place in it is undiminished," said Walker of his impending retirement. "But I've always said I would stop when I'm still ahead with the viewers, rather than wait until there's a general belief that I'm past it."

His place alongside Martin Brundle will be taken at the weekend by roving pit lane reporter James Allen, who is tipped to take over fulltime from Murray next season. Allen has already filled in for Walker in last year's French GP, when Murray was forced to miss the race after dislocating his hip.

Walker will be back behind the microphone as usual for next month's San Marino Grand Prix, while his last grand prix in the commentary box is expected to be Suzuka in October. A book of his grand prix memoirs will be printed next year by publishing giant HarperCollins, and is expected to become a bestseller.