Black Apalachi has a "massive chance" of landing the John Smith's Grand National - but his trainer Dessie Hughes concedes that fellow Irish raider War Of Attrition is the horse they all have to beat at Aintree.

Irish-trained horses have dominated the four-and-a-half-mile contest in recent years with six wins in the last 10 and punters have latched on to Mouse Morris's 2006 Cheltenham Gold Cup winner in the last few days.

As big as 25-1 with most bookmakers at the start of the week, War Of Attrition is now as short as 14-1 with some firms and "by far the best-backed horse in the race", according to Stan James's representative Charlie McCann.

And that is no surprise to Hughes. "He is the best horse in the National. War Of Attrition is going to be hard to beat if he takes to the fences," said Hughes.

"And there's no reason why he shouldn't. He's a very good jumper. He's a class horse and Gold Cup winners are usually good jumpers."

Having departed at the second fence in last year's National, Black Apalachi impressed over the Grand National fences when winning the Becher Chase in November.

Though that 74-length triumph came in heavy ground, Kildare handler Hughes thinks the 10-year-old, set to shoulder 11st 2lb, is equally effective on better going.

He said: "His form is better this year and he has improved. He goes on fast and heavy ground. We'll be hoping that he'd go on nice ground as well because the going at Aintree will be soft. If it's not, they'll water it."

Jockey Denis O'Regan is confident that he will be given the all-clear by doctors later today to partner Black Apalache. The Irishman took a heavy fall at Ayr last Thursday and the results of an MRI scan are expected to show he suffered nothing more than severe bruising to his vertebrae.

Black Apalachi is now a solid 12-1 third favourite with most firms behind Paul Nicholls's My Will and the Jonjo O'Neill-trained Butler's Cabin and Hughes added: "You'd hope he'd have a massive chance. He stays all day. Any horse that takes to the fences will have a good chance and, although it didn't look a strong race, he took to them very well in the Becher."

The National is the one big race missing from Tony McCoy's CV but the champion jockey has yet to announce which horse he will partner. Retired two-time National winner Richard Dunwoody joined McCoy for a schooling session at owner JP McManus's Jackdaws Castle base yesterday and the pair put O'Neill's Aintree hopefuls through their paces.

Dunwoody, who rode outsider Can't Buy Time over specially-built Aintree fences, said: "Tony is planning to speak to JP but he genuinely still doesn't know which one he'll ride."

He added: "Can't Buy Time jumped well. If he takes to Aintree, whoever rides him should have a lot of fun."