The order was sought by Ibrahim Araci, the owner of Native Khan, to prevent Fallon riding a rival horse, Recital.

Mr Araci brought his action over claims that Fallon had broken a “promise” to ride Native Khan and argued that, under the terms of a retainer agreement, he should not be allowed to ride any other horse in the race.

Fallon denied breach of contract and said there had been an “innocent misunderstanding”.

“Kieren is obviously disappointed and very sorry not to be riding in the Derby this afternoon,” said Fallon’s solicitor Christopher Stewart-Moore.

“He wishes the owner of Native Khan the very best of luck and hopes that Pat Smullen has a good ride on Recital too.”

Mr Araci was “thrilled” by the judges’ verdict.

His lawyer, Mehmet Erdogan, said: “He’s thrilled. He always trusted the British legal system, that’s why as a foreigner he invested in this country.

“He believed that justice would never go wrong in the UK.”

Mr Erdogan said that Fallon had “deliberately and cynically” breached a contract.

“Five days before the race, surprisingly and shockingly, he informed our client that he would not be running our client’s horse, but riding a competitor’s horse.

“That was breach of contract,” he said.

He added that it was “unlikely” the jockey would ride a horse owned by Mr Araci in the future.

Native Khan’s trainer Ed Dunlop told Radio 5 Live: “A contract was signed in my office and therefore for the last three-and-a-half weeks, I’ve presumed Kieren was riding my horse and was obviously surprised when he wasn’t.

“The Aracis have got what they wanted.”

In his ruling, Lord Justice Jackson said the status of Fallon did not allow him to avoid the law.

“There is nothing special about the world of racing which entitles the major players to act in flagrant breach of contract,” he said.

He described the injunction as a “grievous blow to the defendant (Fallon)” but said it was his own fault.

“The defendant has brought this present predicament by himself.”

One of the reasons Lord Justice Jackson gave for overturning the decision by Mr Justice MacDuff, was that the possible payment of damages by Fallon would not provide an “adequate remedy” in lieu of an injunction.

In his judgment, the debate over the correct figure would have been complicated.

“It is not easy to speculate what would have been the outcome of a race if different jockeys had been riding different horses.”