However, Andrew Cooper, the director of racing at United Racecourses, stressed that he did not think limiting the field to 20 would in any way affect the stature of Europe’s most valuable and prestigious race.

Indeed the last time that more than 20 runners lined up in the Derby came in 1994 when Erhaab beat 24 rivals.

However it was also in Erhaab’s race that Foyer, ridden by Willie Ryan, was brought down in scrimmaging around Tattenham Corner.

“The trends at the moment do not suggest that we could expect to have more than 20 runners anyway so I think it should be academic,” Cooper said.

“We are not getting the no-hopers we sometimes used to get that made up the numbers.

“It is not a decision that we have taken lightly but I honestly do not think we will have to turn away any good horses.

“If there are more than 20 declared runners then horses will be balloted out by their handicap rating.”

Cooper explained that a fatality at Epsom’s last meeting of the year had encouraged officials to make a firm decision.

“In the last five years, there have only been five or six races over a mile and a quarter and a mile and a half that had above 20 runners,” he said.

“But in September there was a 23-runner handicap over a mile and a half – the last race of the whole season at Epsom – and a horse called Shuwaib was killed in a fall.

“It was then that I really made my mind up and the Jockey Club course inspectors agree with us.

“This is purely a safety issue and it is the safety of every horse and rider that is paramount.”