Edmond is likely to go off favourite

Bookmakers are predicting that betting on the Martell Grand National will top one hundred million pounds for first time.

William Hill believe this weekend will see the biggest plunge of all time on the outcome of the Aintree highlight.

"Although the Grand National is always the biggest betting event of the year, this year's is set to smash all previous records, particularly as we now have internet punters from over 200 different countries logging on to place tax-free bets," said William Hill spokesman Graham Sharpe.

The conditions are also making the race an intriguiging spectacle.

Heavy rain has officially changed the going to heavy which seriously favours the mud-loving horses.

Soggy conditions

There has been plenty of money for Edmond, the Welsh Grand National winner, which thrives on soft ground. His price has come down from 20/1 to 8/1 and he is likely to go off favourite.

There has also been money for last year's winner Papillon and runner-up Mely Moss.

This year's gamble could be Inis Cara - which has been backed down from 50/1 to 20/1 and has been tipped by the Racing Post's Melvyn Collier.

Last year, he tipped Papillon at 33/1 and it went on to win at 10/1 after one of the biggest gambles of modern times.

One of the reasons why the race is so magical is the fact it is so hard to predict the winner.

And with the soggy conditions, only a handful of racers will probably finish the course.

All will be revealed shortly after 1600 BST on Saturday.