The key trials for the Betfred Derby and Oaks at Lingfield on Saturday will be run on the all-weather after a deluge of rain left the turf course unraceable.
The British Horseracing Authority approved the switch following an inspection of the track on Wednesday.
Thunder and lightning hit the course on Tuesday when a total of 23.2mm of rain fell to leave the turf track waterlogged.
The BHA said: “It is considered unlikely that conditions will have improved sufficiently by Saturday to allow any races to take place on the turf safely.
“Therefore, also taking into account the weather forecast suggesting further rain, the BHA has made the decision to switch the surface at this time to offer certainty for connections to confirm their running plans.”
Entries for the card, including the Lingfield Derby Trial, Oaks Trial and Chartwell Fillies’ Stakes will be cancelled and re-opened for entries until 12 noon Thursday with final declarations to be made on Friday.
The Derby Trial had attracted 14 entries including the Charlie Appleby-trained Military Order and two horses trained by Aidan O’Brien, Gooloogong and Bertinelli. Both stables were also represented in the Oaks Trial.
Lingfield’s turf course, which is left-handed with an uphill climb and descent to the straight, provided a similar test to the challenge that Epsom presents. The all-weather track is a more conventional flat oval.
