Bookmakers fear they could lose millions of pounds if former Olympic cyclist Victoria Pendleton manages to pull off an unlikely win at the Cheltenham Festival.
The Bedfordshire cyclist turned amateur jockey will ride Pacha Du Polder in the Foxhunter Chase at 16.10 today.
The 35-year-old only took up the sport a year ago and bookies say her celebrity status has captured the public's imagination.
The odds on Victoria Pendleton winning the Foxhunter Chase.
Foxhunter Chase odds (courtesy of Paddy Power)
On the Fringe - 11/4
Paint the Clouds - 6/1
Aupcharlie - 8/1
It Came To Pass - 9/1
Marito - 9/1
Mendip Express - 12/1
Pacha Du Polder - 20/1
Speaking to Good Morning Britain earlier this week, Pendleton said that just getting round would be an achievement.
Ultimately there are going to be some very experienced amateur jockeys in that race. For me to get round would be winning and I feel I've already won in some respects because I've found a sport that I absolutely adore.
Pendleton has had a mixed start to her racing career.
She fell off her horse in her first race at Fakenham but recovered from the setback to win at Wincanton 10 days later.
There's been no shortage of support for her on Twitter, with Team GB among those wishing her good luck.