The Scottish Grand National will be put back as a mark of respect for the funeral of the Duke of Edinburgh.
Ayr's showpiece event was due to take place on Saturday, April 17 but will now be rescheduled for Sunday, April 18.
Prince Philip's funeral will start at 3pm on Saturday and the British Horseracing Authority (BHA) has today stated that no racing will take place between 2.45pm and 4.15pm.
Ayr's Friday fixture will go ahead as planned and Sunday's feature races, including the Scottish National itself, will be broadcast live on ITV.
Meetings at Newbury, Bangor-on-Dee in Wales, Thirsk, Brighton and Nottingham will also have their cards affected. The BHA will confirm race start times tomorrow.
Last year's Scottish Grand National was cancelled due to the Covid pandemic. The meetings on Friday and Saturday will be behind closed doors.
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The 2019 edition of the race was won by Irish raider Takingrisks at 25/1 with Sean Quinlan in the saddle.
Meanwhile, football matches are also likely to be moved with the fourth round of the William Hill Scottish Cup – featuring Kilmarnock's home clash with League One Montrose and the Old Firm derby – scheduled to take place. In the SPFL Championship, Ayr United are due to travel to Arbroath.
The English Football League (EFL) confirmed last night that no fixtures will be played at 3pm next Saturday.
The Duke of Edinburgh passed away peacefully on Friday morning at the age of 99 at Windsor Castle. In a statement, Buckingham Palace said: "The Royal Family join with people around the world in mourning his loss."
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