Champion jumper Kauto Star is only 50-50 to run in this month’s Cheltenham Gold Cup after a fall, trainer Paul Nicholls has announced.

Nicholls said his dual Gold Cup winner, a crowd favourite with British punters, had taken a tumble while being schooled by jockey Ruby Walsh at Nicholls’s yard in Somerset, south-west England, last week.

“There is no easy way to say this, but Kauto Star is only fifty-fifty to make the Cheltenham Gold Cup after a fall schooling,” Nicholls said in a blog for Betfair.

“As a trainer, it is all too easy to sit on information when it comes to your horses.

“But..in my opinion, the public have a right to know. In many ways, he is as much theirs, as (owner) Clive Smith’s and ours. So I am sad to report that his participation at the Cheltenham Festival is in doubt.

“Kauto took a tumble when Ruby schooled him at the end of last week. I say tumble, but in truth it was a pretty awful fall.

“He has had the best veterinary and physiotherapy care possible but we hoped he would be showing more improvement by now.”

Kauto Star had been second-favourite for the Gold Cup behind last year’s winner Long Run after beating the reigning champion twice this season.

“He is still cantering each day but I can assure you right now that Kauto Star won’t be going anywhere near Cheltenham unless we are all convinced he is 110 per cent right,” Nicholls said.

“Even if there is the slightest doubt in our minds, then he stays at home.

“It will be devastating for all concerned if Kauto Star wasn’t able up to line up on March 16 and try to win a third Gold Cup because he has been in the form of his life this season.

“But one thing I think we have all learned with Kauto is never to write him off. But at this stage his participation does hang in the balance.”

The annual Cheltenham Festival is the cornerstone of the British jump racing season, with the Gold Cup the jewel in the crown for many enthusiasts, even if the Grand National race at Liverpool is better known to the general public.