Updated Cheltenham Festival: Constitution Hill a doubt for Champion Hurdle and going likely to be soft for opening day

Nicky Henderson is not giving up hope of Constitution Hill being able to defend his Unibet Champion Hurdle crown and will have his unbeaten superstar scoped again on Friday, after a below-par workout at Kempton Park on Tuesday put his participation in doubt.

As has become tradition, Henderson took several of his Festival contenders for a spin at the Sunbury circuit, including Constitution Hill, whose only start this season was in the Christmas Hurdle at Kempton.

Bookmakers were quick to suspend the betting markets in the wake of the work, and the Seven Barrows trainer said his superstar had scoped badly following it.

"Unfortunately, in a routine gallop this morning, Constitution Hill was very disappointing and it transpires, after the vet has scoped him, that there is evidence of mucus," said Henderson.

"We're taking a sample of it to a laboratory to analyse it, which will tell us about the significance of it and we should know more after that.

"Last week, he worked brilliantly and he was scoped 10 days ago, but these things happen, just like it did with him earlier in the year [having to miss Cheltenham on Trials day in January].

"Horses are like humans, look how many people had the awful cough around Christmas that took ages to get rid of."

He went on: "The vets still think it could clear up in a week and all his serious work has been done already, whether he makes it [to Cheltenham] will depend on the severity of it.

"He was disappointing this morning working with Sir Gino, who he has worked with in the past. He would normally go easily with him, but this morning he couldn't, so Nico [de Boinville] realised all was not well and wasn’t hard on him.

"Obviously, the mucus was affecting him. He’s not coughing, he’s just got a