Unioniste looking best of Nicholls contenders

The champion trainer also saddles last year’s fifth Rocky Creek, Rebel Rebellion and Mon Parrain, who is owned by Yorkshire businessman John Cotton and will be ridden by 17-year-old Sean Bowen, who is bidding to become the second-youngest jockey to conquer Aintree in the history of the race.

Nicholls said: “Unioniste’s form looks a whole better as he was third to Gold Cup winner Coneygree in the Denman Chase at Newbury. We have obviously trained him for the Grand National and he is an improving horse.

“Ruby Walsh always said to me that this horse could be the next real Aintree candidate. He has lots of experience, even though he is only a seven-year-old, as he was going round Auteuil when he was three and won the December Gold Cup at Cheltenham when he was four. The trip will suit him, as long as there is plenty of cut in the ground. He stays, jumps and is a real candidate.

“He and Rocky Creek have been trained specially for the race and we missed Cheltenham. Rocky Creek was very impressive at Kempton and he is in a better place this season. He and Unioniste are the main two, but you never know – all of them deserve to run in the National.”

Leighton Aspell enjoyed his moment in the sun last year aboard Pineau De Re, but this time rides Hennessy hero Many Clouds for Oliver Sherwood.

Many Clouds, a former Wetherby winner, disappointed in the Gold Cup. “I’ve got it in the back of my mind that he didn’t run his race,” said Sherwood. “It was a tough call for Leighton, getting off a National winner, but they have a very able substitute in Daryl Jacob.”