Irish trio have a crack at fav in World Hurdle Alpha Des Obeaux, Lieutenant Colonel and Martello Tower have the unenviable task of taking on Thistlecrack in the Ryanair World Hurdle at the Cheltenham Festival on Thursday. Alpha Des Obeaux warmed up with victory in the Galmoy Hurdle, while fellow Gigginstown House Stud representative Lieutenant Colonel was second in the Boyne Hurdle on his comeback. Martello Tower won the Albert Bartlett for Mags Mullins 12 months ago but has only been seen twice since, most recently when third behind Alpha Des Obeaux at Gowran Park. Colin Tizzard's Thistlecrack is the leading light among the 13 declarations, though. The eight-year-old has excelled in the staying division this term and will again go head to head with Cole Harden, who won this race last year. The Warren Greatrex-trained Cole Harden finished third behind Thistlecrack on his seasonal debut in the Long Distance Hurdle at Newbury in November. Last year's runner-up Saphir Du Rheu is back for another go and will be joined in the line-up by long-absent stablemate Aux Ptits Soins. At Fishers Cross, Whisper and Un Temps Pour Tout finished fourth, fifth and sixth respectively last season and are once again back in the hunt. Whisper will be accompanied by his Nicky Henderson-trained stablemate Bobs Worth, the 2013 Gold Cup winner. Charlie Longsdon has declared Kilcooley, with the 13-year-old Knockara Beau set to fly the flag for George Charlton.