The biggest betting day for UK horse racing has arrived as the world's most famous steeplechase race is set to take place at Aintree Racecourse.

Forty runners and riders will be participating in the four-mile, four-furlong (7.2km) course.

Last year's winner Many Clouds will lining up once again in a bid winning the race back-to-back emulating the feat of legendary Red Rum who won in 1973 and 1974.

Twice winning jockey Ruby Walsh will miss the showpiece after fracturing his wrist on Friday, trainer Willie Mullins said.

In a change from tradition, the famous race will start an hour later than usual at 17:15 BST.