There will be a minute's silence when the horses are at the start for the opening races at both today's meetings, Hamilton and Hexham, and racing is likely to be cancelled on the day of her funeral. The next meeting at Ascot, the Queen's own course, is not until 27 and 28 September.
The Jockey Club's spokesman, David Pipe, said: "It will be up to the British Horse Racing Board to make the final decision. I've spoken to the BHB chief executive, Tristram Ricketts, and he will be consulting various people before they decide what to do. They should be in a position to say something in the next day or so when they have details of the funeral."
The Princess's death naturally overshadowed British success in two of the three main races at Deauville yesterday.
In the Grand Prix de Deauville, there was only one French runner, L'Africain Bleu, in an extraordinarily poor turnout of four for the pounds 56,000 prize -and he finished fourth.
The race was won by the John Dunlop-trained Taipan, ridden by Pat Eddery, who revelled in the testing ground to beat Peter Chapple-Hyam's Camporese by a length with John Gosden's Lord Of Men, ridden by Frankie Dettori, third.
Earlier, Chapple-Hyam's Woodland Melody, ridden by Olivier Peslier, kept her unbeaten record intact, charging five lengths clear of five French rivals in the Prix du Calvados.
In the Prix de Meautry, Criquette Head's Pas De Reponse squeezed through a gap in the closing stages to win on her first run since finishing fourth behind Sleepytime in the 1,000 Guineas. Joe Naughton's Hever Golf Rose finished third.
The winner heads next for the Prix de l'Abbaye at Longchamp on Arc day, raising the rare prospect of the home side mounting a realistic defence of their most prestigious sprint.
The Arc favourite, Helissio, will have Bijou D'Inde among his rivals when he takes on the specialist milers in a rather peculiar prep for the Arc in next Sunday's Prix du Moulin at Longchamp.
Contrary to the wishes of his trainer, Elie Lellouche, Helissio contests the Moulin rather than the following Sunday's Prix Foy over the Arc distance at the request of his owner, Enrique Sarasola.
Bijou D'Inde has been out of action since being brought down in the Dubai World Cup in April. His trainer, Mark Johnston, said: "He's fine now and should go to France. It's going to be tough starting at that level but there are not many other options. Whatever happens, it is planned to retire Bijou D'Inde at the end of the season."
Just embarking on what seems likely to be a glorious career is Kilimanjaro, who earned a 16-1 quote for the 1998 Derby from the Tote after a devastating win at Sandown on Saturday.
Kilimanjaro, who cost 500,000 guineas as a yearling, won by eight lengths and will now go for either the Royal Lodge Stakes or the Racing Post Trophy.