First Minister Alex Salmond has warned that "serious job losses" are looming in the horse racing industry unless action is taken by the UK Government.
The SNP leader, a keen racing fan and former tipster, will present the Gold Cup at Ayr Racecourse on Saturday and has called for more urgency on the future ownership of the Tote.
The Horse Racing Levy Board, the mechanism which funds the sport, has seen income fall by almost £40 million as many betting operations move offshore to avoid UK tax.
Mr Salmond said: "There have been no steps to address the reformation of the Horse Racing Levy Board, which has seen income slip from £115 million three years ago to a projected £76.5 million this year.
"Horse racing in Scotland is worth £213 million to the economy and generates in excess of £60 million for tourism - but if the levy income continues to slip at this rate, we could be looking at serious job losses across Scottish racing.
"The Westminster Government has to act now to protect the second biggest sport in the country and protect 18,600 full-time equivalent jobs within its core industry."
The board collects a levy from betting profits to finance a range of activities, with over half going on prize money.
A campaign has already been launched within the industry for an overhaul of the levy system.
Its falling income is a "major concern" for Scottish and British horse racing, Mr Salmond added.
He went on: "Like many sports, racing is having to ride the storm of economic turbulence and it is essential that the Westminster Government act now."