Bookies across the country are expecting to take more than £40m on the one race alone.

With rain fall overnight confined to a few light showers Epsom officials were giving the going as good.

The Derby will attract up to £40m in bets

There were fears three horses had been stranded in Ireland, where they are trained by Aidan O'Brien, when the plane scheduled to bring them to Britain was delayed by fog on its out-bound journey.

But Second Empire, King of Kings and Saratoga Springs finally left Shannon Airport on Saturday morning for the scheduled hour-long flight.

They made the short journey to Epsom with a police escort in time for the big race but the scare has put off punters.

Graham Sharpe, of William Hill, said: "It is not the ideal preparation for the race."

Already the housewives' choice Frankie Detorri and Cape Verdi moved into the favourite spot with Ladbrooke's today at a price of 3-1.

Despite being granted a 5lb weight advantage by the racing authorities only six fillies in the 218-year history of the race have won it and the last of those was Fifinella during the First World War.

Cape Verdi is only the fifth filly to run in the Derby since 1919, and her chances are boosted by star jockey Frankie Dettori, champion jockey in 1995 and the only man to have steered all seven rides to victory in a single meeting.

Cape's owners, the Dubai-based Godolphin stable, have paid a £75,000 supplement to allow the daughter of Caerleon to run in the Vodafone Derby and are obviously confident of a good showing.

Tipster Rob Hartnett and Epson general manager Stephen Wallis look ahead to the race

Richard Hannon, one of Britain's top trainers, told BBC News online: "She is a special filly and Godolphin didn't have a good Derby colt so they decided to run her in the Derby."

He said there was no reason why fillies could not beat colts, bearing in mind the weight advantage they are handed.

Mr Hannon, who does not have a runner in this year's Derby, said: "Fillies and colts take each other on in all sorts of races and there is no reason why they shouldn't.

Frankie Dettori will celebrate in characteristic style if Cape Verdi wins

"She can win because she is a fine, big filly with lots of speed and her pedigree suggests she will stay the distance."

He said: "Epsom is not a mugs' course. It leans in and it leans out and a horse needs to be well-balanced as well as fast."

Older horses of the opposite sex compete with each other more often, especially over fences.

The BBC's Racing Correspondent, Clare Balding, said Cape Verdi was more muscular than most fillies and had a better attitude: "She doesn't mess about on the course, she concentrates. My feeling is that she will win."