Buveur D'Air and Apple's Jade are among 14 confirmations for the Unibet Champion Hurdle at Cheltenham on Tuesday.
Nicky Henderson's dual winner Buveur D'Air will bid to become the sixth horse in history to win the two-mile hurdling crown three times - and the first since fellow JP McManus-owned star Istabraq (1998, 1999 and 2000).
However, he looks set to face his toughest test to date next week as he will need to concede 7lb to superstar mare Apple's Jade.
Gordon Elliott's charge claimed her 10th victory at Grade One level with a scintillating display in the Irish Champion Hurdle at Leopardstown last month and disputes favouritism with Buveur D'Air as she bids to become the fifth mare to claim Champion Hurdle glory.
The last mare to achieve the feat was Annie Power and her trainer, Willie Mullins, has another leading contender from the distaff division in Laurina.
The daughter of Spanish Moon is unbeaten in six starts since joining Ireland's perennial champion trainer and is already a Festival winner having landed the Dawn Run Mares' Novices' Hurdle last March by a jaw-dropping 18 lengths.
Mullins could also call upon last year's runner-up Melon and the improving Sharjah.
Apple's Jade could be joined by stablemate Farclas, while the potential Irish challenge is completed by Gavin Cromwell's Espoir D'Allen, the Henry de Bromhead-trained Petit Mouchoir and Supasundae from Jessica Harrington's yard.
Henderson also has International Hurdle winner Brain Power and smart mare Verdana Blue - who beat Buveur D'Air in the Christmas Hurdle at Kempton - in the mix.
Ben Pauling's Global Citizen, Colin Tizzard's Vision Des Flos and the Evan Williams-trained Silver Streak complete the acceptors.