Claire Williams says her legendary father will be "face down on the desk" on the day he retires from his role as team principal.

Claire, 38, is now the Grove team's deputy and undoubtedly first in line to succeed her father Sir Frank, who founded his racing team almost 50 years ago.

In the late 70s, Williams - now 73 and believed to be one of the world's oldest tetraplegics - founded his British-based F1 team alongside Patrick Head, who has since retired.

But Claire says her father is not going to follow suit.

"Frank is TP (team principal)," she told the Guardian newspaper. "Always has been, always will be, until we find him one day face down on the desk."

Sir Frank spent some considerable time in hospital last year, but he is once again attending Grands Prix in 2015. But his travails in 2014 triggered speculation Claire is his obvious successor in the top job.

However, she says Frank remains as passionate today as he ever was.

"Frank is in there 24-7 -- he's in the office more than any of us. He loves it, he's passionate about it.

"Frank is there, he always will be and he has no plans to retire," said Claire. "It wouldn't be the same without him."