Strong Irish challenge for the Ladbroke
Thomas Edison (noseband) is a Ladbroke contender
(Healy Racing Photos)
Henderson's nine-year-old has enjoyed something of a renaissance this season after being restricted by injury.
Third in the Queen Mother Champion Chase in 2009, Petit Robin has switched with great effect back to hurdles with solid wins at Ascot and Sandown already this term.
Henderson's raid on this valuable prize is backed up by Cash and Go, Lyvius and First In The Queue.
Alan King has the strongly-fancied Balder Succes while Tom George has declared Racing Post Hurdle victor Olofi.
The lightly-raced Ranjaan represents the Paul Nicholls stable with David Pipe has two likely outsiders in Kazlian and Dan Breen.
Jonjo O'Neill's It's A Gimme and the Brian Ellison-trained Bothy feature in a fascinating list.
There is also a strong challenge from Ireland in the shape of Gordon Elliott's Cause Of Causes, Willie Mullins' Rattan, Eddie Harty's Princeton Plains and Thomas Edison from Tony Martin's stable.
Eight runners were declared for the Long Walk Hurdle at Ascot on Saturday after Big Buck's was the only defection at the 48-hour final declaration stage.